Update dependencies and tests

.phpunit.result.cache

@@ -0,0 +1 @@
+C:37:"PHPUnit\Runner\DefaultTestResultCache":3296:{a:2:{s:7:"defects";a:0:{}s:5:"times";a:53:{s:34:"DriverFactoryTest::can_init_driver";d:0.007;s:63:"DriverFactoryTest::will_throw_exception_if_using_invalid_driver";d:0.001;s:42:"DriverFactoryTest::can_get_list_of_drivers";d:0;s:57:"BaseCurrencyDriverTest::init_will_properly_set_parameters";d:0.002;s:53:"BaseCurrencyDriverTest::will_properly_switch_to_https";d:0;s:47:"BaseCurrencyDriverTest::from_sets_base_currency";d:0.001;s:47:"BaseCurrencyDriverTest::to_sets_target_currency";d:0;s:42:"BaseCurrencyDriverTest::setters_are_fluent";d:0;s:49:"BaseCurrencyDriverTest::can_set_and_retrieve_date";d:0;s:48:"BaseCurrencyDriverTest::can_perform_api_requests";d:0.003;s:39:"CurrencyLayerTest::can_get_latest_rates";d:0;s:43:"CurrencyLayerTest::can_get_historical_rates";d:0;s:64:"CurrencyLayerTest::fails_to_get_historical_rates_if_date_not_set";d:0;s:47:"CurrencyLayerTest::can_convert_currency_amounts";d:0;s:47:"CurrencyLayerTest::can_handle_response_failures";d:0;s:42:"ExchangeRatesApiTest::fails_to_set_api_key";d:0;s:42:"ExchangeRatesApiTest::can_get_latest_rates";d:0;s:46:"ExchangeRatesApiTest::can_get_historical_rates";d:0;s:67:"ExchangeRatesApiTest::fails_to_get_historical_rates_if_date_not_set";d:0;s:55:"ExchangeRatesApiTest::fails_to_convert_currency_amounts";d:0;s:50:"ExchangeRatesApiTest::can_handle_response_failures";d:0;s:33:"FixerIoTest::can_get_latest_rates";d:0;s:37:"FixerIoTest::can_get_historical_rates";d:0;s:58:"FixerIoTest::fails_to_get_historical_rates_if_date_not_set";d:0;s:41:"FixerIoTest::can_convert_currency_amounts";d:0;s:41:"FixerIoTest::can_handle_response_failures";d:0;s:44:"MockCurrencyDriverTest::can_get_latest_rates";d:0;s:48:"MockCurrencyDriverTest::can_get_historical_rates";d:0;s:46:"MockCurrencyDriverTest::can_convert_currencies";d:0;s:37:"OpenExchangeRatesTest::can_set_app_id";d:0;s:43:"OpenExchangeRatesTest::can_get_latest_rates";d:0.002;s:47:"OpenExchangeRatesTest::can_get_historical_rates";d:0.002;s:68:"OpenExchangeRatesTest::fails_to_get_historical_rates_if_date_not_set";d:0.001;s:51:"OpenExchangeRatesTest::can_convert_currency_amounts";d:0.001;s:51:"OpenExchangeRatesTest::can_handle_response_failures";d:0.001;s:32:"DateHelperTest::can_parse_a_date";d:0.001;s:33:"DateHelperTest::can_format_a_date";d:0.001;s:33:"DateHelperTest::can_create_a_date";d:0.001;s:45:"DateHelperTest::can_get_current_date_and_time";d:0.001;s:36:"DateHelperTest::can_get_current_date";d:0.001;s:60:"ConversionResultTest::construct_will_properly_set_parameters";d:0;s:50:"ConversionResultTest::returns_all_conversion_rates";d:0;s:72:"ConversionResultTest::fails_to_convert_if_target_currency_does_not_exist";d:0;s:72:"ConversionResultTest::fails_to_convert_if_source_currency_does_not_exist";d:0;s:52:"ConversionResultTest::can_convert_between_currencies";d:0;s:71:"ConversionResultTest::fails_to_retrieve_rate_if_currency_does_not_exist";d:0;s:56:"ConversionResultTest::retrieves_currency_conversion_rate";d:0;s:78:"ConversionResultTest::fails_to_change_base_currency_if_currency_does_not_exist";d:0;s:45:"ConversionResultTest::can_reset_base_currency";d:0;s:46:"ConversionResultTest::can_change_base_currency";d:0;s:31:"SymbolTest::can_get_all_symbols";d:0;s:33:"SymbolTest::can_get_a_symbol_name";d:0;s:41:"SymbolTest::can_get_a_list_of_all_symbols";d:0;}}}

.travis.yml

@@ -1,8 +1,6 @@
 language: php
 
 php:
-  - "7.1"
-  - "7.2"
   - "7.3"
   - "7.4"
   - "8.0"
@@ -15,7 +13,7 @@ env:
 
 install:
   - curl -s http://getcomposer.org/installer | php
-  - php composer.phar install --dev --no-interaction
+  - php composer.phar install --no-interaction
   - curl -L https://codeclimate.com/downloads/test-reporter/test-reporter-latest-linux-amd64 > ./cc-test-reporter
   - chmod +x ./cc-test-reporter
   - ./cc-test-reporter before-build

README.md

@@ -39,7 +39,7 @@ _If you want to see more services added, feel free to [open an issue](https://gi
 
 ## Prerequisites 📚
 
-* `PHP 7.1` or higher (Tested on: PHP `7.1` ✅, `7.2` ✅, `7.3` ✅ and `7.4` ✅)
+* `PHP 7.3` or higher (Tested on: PHP ✅, `7.3` ✅ and `7.4` ✅)
 * The [`composer`](https://getcomposer.org) dependency manager for PHP
 * An account with one or more of the [API providers](#supported-apis-) listed above
 

phpunit.xml

@@ -1,31 +1,25 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<phpunit backupGlobals="false"
-         backupStaticAttributes="false"
-         bootstrap="vendor/autoload.php"
-         colors="true"
-         convertErrorsToExceptions="true"
-         convertNoticesToExceptions="true"
-         convertWarningsToExceptions="true"
-         processIsolation="false"
-         stopOnFailure="false">
-    <testsuites>
-        <testsuite name="Package Test Suite">
-            <directory suffix=".php">./tests/</directory>
-        </testsuite>
-    </testsuites>
-    <filter>
-        <whitelist processUncoveredFilesFromWhitelist="true">
-            <directory>./src</directory>
-            <exclude>
-                <directory>./vendor</directory>
-                <directory>./tests</directory>
-                <directory>./examples</directory>
-            </exclude>
-        </whitelist>
-    </filter>
-    <logging>
-        <log type="coverage-text" target="php://stdout"/>
-        <log type="coverage-clover" target="build/cov.xml"/>
-        <log type="junit" target="build/junit.xml"/>
-    </logging>
+<phpunit xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" backupGlobals="false" backupStaticAttributes="false" bootstrap="vendor/autoload.php" colors="true" convertErrorsToExceptions="true" convertNoticesToExceptions="true" convertWarningsToExceptions="true" processIsolation="false" stopOnFailure="false" xsi:noNamespaceSchemaLocation="https://schema.phpunit.de/9.3/phpunit.xsd">
+  <coverage processUncoveredFiles="true">
+    <include>
+      <directory>./src</directory>
+    </include>
+    <exclude>
+      <directory>./vendor</directory>
+      <directory>./tests</directory>
+      <directory>./examples</directory>
+    </exclude>
+    <report>
+      <clover outputFile="build/cov.xml"/>
+      <text outputFile="php://stdout"/>
+    </report>
+  </coverage>
+  <testsuites>
+    <testsuite name="Package Test Suite">
+      <directory suffix=".php">./tests/</directory>
+    </testsuite>
+  </testsuites>
+  <logging>
+    <junit outputFile="build/junit.xml"/>
+  </logging>
 </phpunit>

tests/Drivers/BaseCurrencyDriverTest.php

@@ -21,7 +21,7 @@ class BaseCurrencyDriverTest extends TestCase
 
   private $valid_json_response = '{ "success": true, "base": "USD", "date": "2019-06-11", "rates": { "JPY": 107.346001, "EUR": 0.813399 } }';
 
-  protected function setUp()
+  protected function setUp(): void
   {
     $mock = new MockHandler([
       new Response(200, [], $this->valid_json_response),

tests/Drivers/CurrencyLayerTest.php

@@ -20,7 +20,7 @@ class CurrencyLayerTest extends TestCase
 
   private $mockHandler;
 
-  protected function setUp()
+  protected function setUp(): void
   {
     $this->mockHandler   = new MockHandler();
     $this->currencyLayer = DriverFactory::make('currencylayer', new Client(['handler' => $this->mockHandler]));

tests/Drivers/ExchangeRatesApiTest.php

@@ -21,7 +21,7 @@ class ExchangeRatesApiTest extends TestCase
 
   private $mockHandler;
 
-  protected function setUp()
+  protected function setUp(): void
   {
     $this->mockHandler      = new MockHandler();
     $this->exchangeRatesApi = DriverFactory::make('exchangeratesapi', new Client(['handler' => $this->mockHandler]));

tests/Drivers/FixerIoTest.php

@@ -20,7 +20,7 @@ class FixerIoTest extends TestCase
 
   private $mockHandler;
 
-  protected function setUp()
+  protected function setUp(): void
   {
     $this->mockHandler = new MockHandler();
     $this->fixerIo     = DriverFactory::make('fixerio', new Client(['handler' => $this->mockHandler]));

tests/Drivers/MockCurrencyDriverTest.php

@@ -15,7 +15,7 @@ class MockCurrencyDriverTest extends TestCase
   /** @var BaseCurrencyDriver */
   private $mockCurrencyDriver;
 
-  protected function setUp()
+  protected function setUp(): void
   {
     $this->mockCurrencyDriver = DriverFactory::make('mock');
   }

tests/Drivers/OpenExchangeRatesTest.php

@@ -20,7 +20,7 @@ class OpenExchangeRatesTest extends TestCase
 
   private $mockHandler;
 
-  protected function setUp()
+  protected function setUp(): void
   {
     $this->mockHandler       = new MockHandler();
     $this->openExchangeRates = DriverFactory::make('openexchangerates', new Client(['handler' => $this->mockHandler]));

tests/Results/ConversionResultTest.php

@@ -16,7 +16,7 @@ class ConversionResultTest extends TestCase
   /**
    *
    */
-  protected function setUp()
+  protected function setUp(): void
   {
     $this->classUnderTest = new ConversionResult(Symbol::USD, 1560293762, [
       'EUR' => 0.88,