adding pep 8 checks in unit tests

.travis.yml

@@ -17,12 +17,19 @@ python:
 #  - "3.3"
 # command to install dependencies
 install: 
-  - pip install -e . --use-mirrors
+  - pip install -e .
+  - "if [[ $TEST_PEP8 == '1' ]]; then pip install pep8; fi"
   - pip install passlib
   - pip install coveralls
 # command to run tests
 script: 
   - coverage run --source=ldapcherry setup.py test
+  - "if [[ $TEST_HIREDIS == '1' ]]; then pip install hiredis; fi"
+script: "if [[ $TEST_PEP8 == '1' ]]; then pep8 --repeat --show-source --exclude=.venv,.tox,dist,docs,build,*.egg,tests,misc .; else coverage run --source=ldapcherry setup.py test; fi"
+matrix:
+  include:
+    - python: "2.7"
+      env: TEST_PEP8=1
 after_success:
   - coveralls
 after_failure: