Type hints fix (#5)

* WIP: Added type hints, still waiting on resolution of [so issue](https://stackoverflow.com/q/54425358/4200103).

* Added nox, updated travis.yml

* Added script to remove type-hints for all python versions below 3.6

* forgot to add test-requirements.txt

* removed 2.6 support

* - moved testing for different python versions from travis to nox
- added auto stripping of type hints

* decided to keep support for 2.6 until we need a lib that does not support it

* forgot to delete something from travis.yml

* fixed travis.yml for name of pytests method inside nox file

* moved type hints to .pyi stubs on deploy to prevent python version compatibility issues

.travis.yml

@@ -3,6 +3,7 @@ python:
 - '3.6'
 install:
 - python setup.py install
+- pip install mypy
 - pip install strip-hints
 - pip install -r test-requirements.txt
 jobs:
@@ -23,6 +24,8 @@ jobs:
 
 after_success:
 - python-codacy-coverage -r coverage.xml
+- stubgen ascii_canvas --recursive -o .
+- python strip-type-hints.py
 deploy:
   provider: pypi
   skip_existing: true

setup.py

@@ -6,7 +6,7 @@
     long_description = stream.read()
 
 setup(name='ascii-canvas',
-      version='1.2.2',
+      version='1.2.3',
       author='Paul Schweizer',
       author_email='paulschweizer@gmx.net',
       description='Treat strings like Items on a 2D Canvas.',
@@ -18,8 +18,8 @@
               'Programming Language :: Python',
               'Programming Language :: Python :: 2.6',
               'Programming Language :: Python :: 2.7',
-              'Programming Language :: Python :: 3.3',
               'Programming Language :: Python :: 3.4',
               'Programming Language :: Python :: 3.5',
-              'Programming Language :: Python :: 3.6'
+              'Programming Language :: Python :: 3.6',
+              'Programming Language :: Python :: 3.7'
         ])