Excercise msgpack packing/unpacking when using MockServiceContainer

This will enable developer to catch errors that will not have been
possible when we skipped msgpack packing/unpacking, for example
sending a tuple and expecting a tuple in the service, which shouldn't
work since we don't configure msgpack to convert lists to tuples.
Merge pull request #39 from mouadino/exercise-msgpack

Excercise msgpack packing/unpacking when using MockServiceContainer
Only run tests with 3.4 on travis
Upgraded nose to 1.3.4 for Python 3.4 compatibility

See https://github.com/nose-devs/nose/pull/811
Run tests with Python 3.4 instead of 3.3
Merge pull request #40 from emulbreh/only-34-on-travis

Only run tests with 3.4 on travis