python26 compatibility fix

fix format errors
fix unittests
fix tox & travis configs
CFY-1274 code cleanup
Merge pull request #63 from cloudify-cosmo/CFY-1274-py26-compatebility

python26 compatibility fix
CFY-1318 update tests
CFY-1318 for travis
CFY-1318 for travis
CFY-1318 fix reference to inputs
Merge branch 'master' into CFY-1318-tosca-interfaces

Conflicts:
	cloudify/tests/test_local_workflows.py
CFY-1318 fix bug in local workflow validations
CFY-1318 raise exception for non existent operations
CFY-1318 add test for executing non existent operations
CFY-1318 master
Merge pull request #64 from cloudify-cosmo/CFY-1318-tosca-interfaces

Cfy 1318 tosca interfaces
travis
Merge branch 'master' into CFY-1433-multi-instance-runtime