Add alwaysAllowAccess flag to traffic controller

  + This flag allows access to logs for any app with any credentials,
    thus the traffic controller does not have to talk to cloud controller.
    This is to support deploying loggregator outside of CloudFoundry.

  + Also converts the log_access_authorizer_test to Ginkgo.

Signed-off-by: Matthew McNew <mmcnew@pivotal.io>