Fix proptype warnings and linting

[job13er]

This project uses semver, please check the scope of this pr:

• [ ] #none# - documentation fixes and/or test additions
• [x] #patch# - backwards-compatible bug fix
• [ ] #minor# - adding functionality in a backwards-compatible manner
• [ ] #major# - incompatible API change

CHANGELOG

• Enabled code coverage checking and set an initial baseline coverage
• Fixed propType warnings (resolves #106)
• Enabled propType errors (instead of warnings) within the addon so the above doesn't regress

[coveralls]

Changes Unknown when pulling 584768e0f308dd6a204611881a9a7a1e9bf541d6 on job13er:fix-proptypes into on ciena-frost:master.

[sglanzer-deprecated]

Approved