Removing infinite waits from tests.

Many test cases were doing an infinite wait for the mock server to shutdown. This was more required when the servers were not using ephemeral ports.
Introduced a method of time wait on RxServer and using that method in test.
Removing method deprecated in rxjava-0.0.19.

- toBlockingObservable() is deprecated in favor of toBlocking()
- SubscriptionList class is moved to rxjava util pkg.