Blank lines should not contain any whitespace

Eldarion has decided for open source projects to conform to the blank lines
should not contain whitespace style guideline. We want to do less style guide enforcing with our contributors and make it easier for them to contribute.

This does not mean we won't enforce this style guideline. Consistency is still
king and mixing whitespace lines with no whitespace lines is discouraged.
Add script to run tests and coverage
Add a .gitignore
Attempt to fix travis
Add CONTRIBUTING document
Fixes a potential issue if trying to add payments before the app where the custom User model is defined in the app caching