Added tests for email/password provider

- Added tests for email/password provider (note that some tests are currently skipped for several reasons - not sure how to implement yet, don't pass but should, etc. - but I will get to them later)
- Improved tests for the base FirebaseSimpleLogin constructor
- Minor changes to anonymous auth tests
- Changed Firebase used to run tests because I didn't have access to everything I needed on Rob's Firebase. Will work out a longterm solution with him once he is back in office.