Update .travis.yml

coverage falls over because of the `__pycache__` folder.

Author: wilko77

.travis.yml

@@ -70,5 +70,5 @@ install:
 
 script:
   - nosetests -v --with-timer --timer-top-n 10
-  - if [ "${TESTMODE}" == "full" ]; then coverage run `which nosetests`; coverage report phe/*; fi
+  - if [ "${TESTMODE}" == "full" ]; then coverage run `which nosetests`; coverage report -i phe/*; fi
   - if [ "${USE_WHEEL}" == "1" ]; then python setup.py bdist_wheel; fi