CFY-785 use new rest client
CFY-785 use new rest client
Merge pull request #13 from cloudify-cosmo/feature/CFY-785-use-new-rest-client

CFY-785 use new rest client
CFY-807 change workflow launched status to started
CFY-807 use execution constants
CFY-807 use execution constants
Merge pull request #14 from cloudify-cosmo/feature/CFY-807-wait-for-deployment-creation

Feature/cfy 807 wait for deployment creation
CFY-783 added cancel workflow support to workflows infrastructure and tasks_graph implementation
CFY-783 merge commit