Use a more python-standard test setup

Use `python setup.py test` to run the tests, and a few minor changes
required to support that.

Author: bryanburgers

.travis.yml

@@ -7,5 +7,4 @@ install:
   - pip install flake8
 script:
   - flake8 homu
-  - cd homu
-  - python -m unittest
+  - python setup.py test

homu/tests/__init__.py

@@ -1,5 +1,5 @@
 import unittest
-from parse_issue_comment import parse_issue_comment
+from homu.parse_issue_comment import parse_issue_comment
 
 # Random commit number. Just so that we don't need to come up with a new one
 # for every test.

homu/test_parse_issue_comment.py renamed to homu/tests/test_parse_issue_comment.py

@@ -5,6 +5,7 @@
     version='0.3.0',
     author='Barosl Lee',
     url='https://github.com/barosl/homu',
+    test_suite='homu.tests',
     description=('A bot that integrates with GitHub '
                  'and your favorite continuous integration service'),