Async gearman client.
Require no blocking finally, understood why it was causing a problem...
Added IT tests for gearman
Create an embedded gearman server with a dummy job that success job with success and fail job with fail data
Add tracing in Gearmanclient
Update test according to comments
Fix sbt project for Gearman, was not compiled and tested...
Various fix according to pull request review
 -code style
 -future exception validation in tests
minor code style modif
Upgrade scala-test version so I can Ignore GearmanIntegrationTest(which is not a real test suite)
Merge pull request #29 from wajam/mic-async-gearman-client

[GEARMAN] Async gearman client.