Add support for Python 3.7

Author: hugovk

.travis.yml

@@ -21,6 +21,8 @@ matrix:
             - python-requests
             - python-coverage
             - python-mock
+    - python: 3.7
+      dist: xenial
 
 install:
   - pip install -r tests/requirements.txt

setup.py

@@ -7,9 +7,13 @@
                "Environment :: Plugins",
                "Intended Audience :: Developers",
                "Programming Language :: Python",
+               "Programming Language :: Python :: 2",
                "Programming Language :: Python :: 2.7",
                "Programming Language :: Python :: 3",
                "Programming Language :: Python :: 3.4",
+               "Programming Language :: Python :: 3.5",
+               "Programming Language :: Python :: 3.6",
+               "Programming Language :: Python :: 3.7",
                "Programming Language :: Python :: Implementation :: PyPy",
                "License :: OSI Approved :: Apache Software License",
                "Topic :: Software Development :: Testing"]