Lock handling fix in MarathonHealthCheckManager.
Added Daemon -- companies using Marathon
Merge pull request #768 from farukd/patch-1

Added Daemon -- companies using Marathon
Added DELETE /v2/deployments/{id}?force=true to
cancel a deployment without creating a new one
that rolls back to the previous state.

- Adds MarathonSchedulerService.cancelDeployment
- Fixes #755
Added docs for `DELETE /v2/deployments{id}?force`
Merge pull request #767 from mesosphere/755-delete-deployment-no-rollback

Added DELETE /v2/deployments/{id}?force=true
Setting version to 0.7.4
Setting version to 0.7.5-SNAPSHOT
added compiler flags for

- warnings on unused imports
- warnings on numeric widening
- disabling adapted args (automatic tuple conversion)
- fail the build on compiler warnings

Overall this should lead to increased code quality.
Merge pull request #778 from mesosphere/wip-compiler-flags-drexin

added compiler flags for
updated scala version to 2.11.4
Merge pull request #776 from mesosphere/wip-scala-2.11.4-drexin

updated scala version to 2.11.4
added first play-json formats and removed json4s
fixed some formats, added some and use play-json to serialize AppDefinitions
restructured Formats, added more formats and use play-json in AppsResource