CreateOFForwardingAction checks priority is valid for floodlight and fails if not.

http://jira.i2cat.net:8080/browse/OPENNAAS-1168
Create SDNNetworkFlows with an acceptable priority.

NCLController now sets a priority value that is acceptable by floodlight driver.
http://jira.i2cat.net:8080/browse/OPENNAAS-1159
Add tests for CreateOFForwardingAction checkParams with valid and invalid priorities.

http://jira.i2cat.net:8080/browse/OPENNAAS-1167
Merge pull request #725 from isartcanyameres/fix/floodlight-driver-checks-priority

Fix/floodlight driver checks priority