Update Travis config

Author: rshipp

.travis.yml

@@ -1,17 +1,14 @@
 language: python
 python:
-#  - "2.6"  # unittest.TestCase doesn't have assertIn in 2.6
   - "2.7"
   - "3.3"
-  - "3.4"
   - "3.5"
   - "3.6"
+  - "3.7"
 install:
   - "pip install nose"
   - "pip install coverage"
   - "pip install codacy-coverage"
   - "python setup.py install"
 script:
   - nosetests --with-coverage --cover-package=threatkb --cover-xml
-after_success:
-  - python-codacy-coverage