CFY-1373 use ctx source/target api
CFY-1373 add status code to openstack exceptions
CFY-1318 change interface mappings
Merge pull request #28 from cloudify-cosmo/CFY-1318-tosca-interfaces

CFY-1318 change interface mappings
Merge branch 'master' into CFY-1229-openstack-keypair-type
CFY-1229 updated plugin yaml according to new interface spec