Add notice of Python 2.7 deprecation (#112)

Author: crwilcox

README.rst

@@ -48,6 +48,15 @@ Installation
     `virtualenv <https://virtualenv.pypa.io/en/latest/>`_.
 
 
+Supported Python Versions
+^^^^^^^^^^^^^^^^^^^^^^^^^
+Python >= 3.4
+
+Deprecated Python Versions
+^^^^^^^^^^^^^^^^^^^^^^^^^^
+Python == 2.7. Python 2.7 support will be removed on January 1, 2020.
+
+
 Usage
 -----
 

setup.py

@@ -33,12 +33,14 @@
         'Programming Language :: Python :: 3.4',
         'Programming Language :: Python :: 3.5',
         'Programming Language :: Python :: 3.6',
+        'Programming Language :: Python :: 3.7',
         'Programming Language :: Python :: Implementation :: CPython',
     ],
     description='Client library for the Dialogflow API',
     include_package_data=True,
     long_description=long_description,
     install_requires=install_requires,
+    python_requires='>=2.7,!=3.0.*,!=3.1.*,!=3.2.*,!=3.3.*',
     license='Apache 2.0',
     packages=find_packages(),
     url='https://github.com/dialogflow/dialogflow-python-client-v2',