adds full test coverage for nova, except the matcher (not implemented yet)
tests for load balancer
removing bad implementation of 422 error
negative tests for load balancers
tests for auth
Address review feedback.

Especially, propagate the current timestamp all the way through the
system from the one IReactorTime provided to the mimic core, so that
tests can consistently advance the clock.

(This will be useful later when we add API-level access to the clock, as
well...)
Merge remote-tracking branch 'origin/tests_for_load_balancers' into nova-negative-tests
Propagate current_timestamp through all loadbalancer APIs.
Lint errors.
Merge pull request #82 from rackerlabs/nova-negative-tests

Tests for nova error injection