[director] Add list current locks to director API
[director] Fix type when logging adquiring locks
[cli] Add command to list current locks
Merge remote-tracking branch 'origin/locks' into develop

Signed-off-by: Adam Stegman <astegman@pivotallabs.com>

Conflicts:
	bosh_cli/lib/cli/director.rb
	bosh_cli/spec/unit/director_spec.rb
	director/lib/director/api/controller.rb
	director/spec/unit/api/controller_spec.rb
Refactor locks unit tests

Signed-off-by: Adam Stegman <astegman@pivotallabs.com>
Add integration tests for locks

Signed-off-by: Adam Stegman <astegman@pivotallabs.com>