Run github_webhook setup and virtualenv only on Python 3

Author: AidanDelaney

setup.py

@@ -9,7 +9,7 @@
       license='Apache 2.0',
       packages=["github_webhook"],
       install_requires=['flask==1.0.2'],
-      tests_require=['mock', 'nose'],
+      tests_require=['mock', 'pytest', 'nose'],
 
       classifiers=[
           'Development Status :: 4 - Beta',
@@ -21,7 +21,6 @@
           'Operating System :: MacOS :: MacOS X',
           'Operating System :: Microsoft :: Windows',
           'Operating System :: POSIX',
-          'Programming Language :: Python :: 2',
           'Programming Language :: Python :: 3',
           'Topic :: Software Development :: Version Control'
           ],

tox.ini

@@ -1,13 +1,12 @@
 [tox]
-envlist = py27,py36,py37,pypy,pypy3,flake8
+envlist = py36,py37,pypy,pypy3,flake8
 
 [testenv]
 deps =
      pytest
      pytest-cov
      flask
-     six
-     py{27,py}: mock
+     pypy: mock
 commands = pytest -vl --cov=github_webhook --cov-report term-missing --cov-fail-under 100
 
 [testenv:flake8]