add in memory implementations of classes needed for an in memory
stream file admin. This is needed because the current in memory
stream admin throws unsupported operation exceptions for config
related methods, which are required for CDAP-693.
CDAP-672 Update to use Tephra 0.3.1
shorten fully qualified name.
Merge pull request #653 from caskdata/feature/in-memory-stream-admin

add in memory implementations of classes needed for an in memory
Merge pull request #656 from caskdata/feature/tephra-0.3.1

CDAP-672 Update to use Tephra 0.3.1
(CDAP-355) Insecurely pass user id from router to downstream services
Merge pull request #137 from caskdata/feature/router-pass-user

(CDAP-355) Insecurely pass user id from router to downstream services
Merge branch 'develop' of github.com:caskdata/cdap into feature/get_current_runId_appfabric
minor fixes and refactoring