Swiching to argonaut for json.
Still through argonaut migration.
Merge branch 'master' of https://github.com/gneuvill/syncisssues

Conflicts:
	src/main/scala/fr/syncissues/model/package.scala
	src/main/scala/fr/syncissues/services/GitHub.scala
	src/main/scala/fr/syncissues/services/ProjectService.scala
	src/main/scala/fr/syncissues/utils/Conversions.scala
	src/test/scala/fr/syncissues/services/GitHubTest.scala
	src/test/scala/fr/syncissues/services/IceScrumTest.scala