Add 'coverage.py' to travis to generate report

Author: RJMW

.travis.yml

@@ -14,12 +14,12 @@ install:
   - conda info -a
   - conda env create -n test-environment -f environment.yml
   - source activate test-environment
-  - conda install coverage green codecov -c conda-forge
+  - conda install coverage codecov -c conda-forge
   - python setup.py install
 
 script:
   - dimspy --help
-  - python setup.py test
+  - coverage run --source dimspy setup.py test
 
 after_script:
   - python -m codecov