Tidied comments and dropped Python 2.7 support

.travis.yml

@@ -3,13 +3,13 @@ sudo: required
 services:
 - docker
 python:
-- '2.7'
 - '3.5'
 - '3.6'
 install:
-- pip install mypy
+- pip install mypy pycodestyle
 - pip install .
 script:
+- pycodestyle src
 - mypy src --ignore-missing-imports
 notifications:
   email: false

setup.py

@@ -23,7 +23,7 @@
         'Programming Language :: Python :: 3.5',
         'Programming Language :: Python :: 3.6',
     ],
-    python_requires='>=2.7',
+    python_requires='>=3.5',
     install_requires=[
         'requests>=2.0.0',
         'typing>=0.4.1'