Allow overriding Session cookie params

 * Build Cookie expiration time based on the request's server time
 * Allow overriding session cookie params via `session.session_params`
 * Initial integration testing
Compare against new Cookie instance.
No need to do weird use shenanigans w/ $this properties
Create a abstract base class.
Rename AbstractTestCase to TestCase
Time calculation moved to provider.
Reformat provider, simulated time a const.
Merge remote-tracking branch 'simensen/session-cookie-params'

* simensen/session-cookie-params:
  Reformat provider, simulated time a const.
  Time calculation moved to provider.
  Rename AbstractTestCase to TestCase
  Create a abstract base class.
  No need to do weird use shenanigans w/ $this properties
  Compare against new Cookie instance.
  Allow overriding Session cookie params