pypy3 doesn't like regex package.

Author: ikirudennis

.travis.yml

@@ -15,7 +15,7 @@ install:
   - if [[ $REQUIREMENTS == true ]] ; then pip install -r requirements.txt ; fi
   - pip install -U coveralls pytest pytest-cov 'coverage<5' codecov
   - pip install -e .
-  - if [[ ! $TRAVIS_PYTHON_VERSION == 'pypy3' ]] ; then pip install regex; fi
+  - if [[ $TRAVIS_PYTHON_VERSION == 'pypy3' && $REQUIREMENTS == true ]] ; then pip uninstall regex; fi
 # command to run tests
 script: py.test
 after_success: