max and min functions for NumPy arrays and Pint quantities (#186)

* Increment copyright year
* Fix `Pipfile` dependencies
* `aguaclara.core.utility`
  * Update documentation
  * Refactor code
  * Add min/max functions
  * Add optional_arguments decorator

LICENSE

@@ -1,6 +1,6 @@
 MIT License
 
-Copyright (c) 2017 AguaClara
+Copyright (c) 2019 AguaClara
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal

Pipfile

@@ -8,21 +8,21 @@ pandas = "*"
 pint = "==0.8.1"
 scipy = "*"
 onshape_client = "*"
-requests = ">=2.20.0"
-matplotlib = "==3.0.3"
+matplotlib = "==3.0.3" # Supports Python 3.5
 
 [dev-packages]
 codecov = "*"
 coverage = "*"
 pytest = "*"
 pytest-cov = "*"
 Sphinx = "*"
-sphinx_rtd_theme = "==0.4.0"
-aguaclara = {editable = true,path = "."}
+sphinx_rtd_theme = "*"
+aguaclara = {editable = true, path = "."}
 pytest-runner = "*"
 requests = ">=2.20.0"
 rope = "*"
 pylint = "*"
+autopep8 = "*"
 
 [requires]
 python_version = "3.6"