Remove expired sessions
Session keepalive
Remove collections of expired sessions
pep8 compliance
Remove unnecesssary asserts
Test session expiration and initial app loading.
Refactor keep alive tests.
Add scheduler and mock library to requirements.txt
Merge pull request #2 from FuegoFro/ryan_session_expiration

Ryan session expiration
Merge pull request #160 from rcchan/session_expiration

Session expiration