add plugin rest implementation
add fail tests
Merge branch 'develop' of github.com:caskdata/coopr into COOPR-526
update after review, change http handler
update  getPluginTypeMap method
Merge branch 'develop' of github.com:caskdata/coopr into COOPR-526

Conflicts:
	coopr-rest-client/src/main/java/co/cask/coopr/client/rest/PluginRestClient.java