Exposing a test suite for implementers

[wavded]

Throwing this out for discussion. It seems like a core test suite for store implementors would be handy to ensure compliance with express-session. Winston did this for loggers. Implementors could include express-session in their test suite passing in their store, and have it run through a series of compliance tests.

[Fishrock123]

See also pillarjs/pillarjs.github.io#4

[dougwilson]

we also want to change the interface between stores and session anyway, because right now it sucks

[Magnitus-]

I made some integration tests between my store and the express-session project if it helps:
https://github.com/Magnitus-/ExpressSessionMongoDB/blob/master/test/IntegrationTests.js

There are slight mongodb deps that could be taken out (they are in the require statements and the Setup function). Unfortunately, the coupling with to the nodeunit library (I know a lot of people prefer mocha) are tighter.

Overall, I think the expected store API needs better documentation such that people don't need to look at existing implementations to figure out how it should be implemented.