be explicit about urllib import and remove conditional urllib(2) import

urllib and urllib2 have been in the python stdlib since at least
python-2.3.  There's no reason to conditionalize it.

Fixes https://github.com/ansible/ansible/issues/11322

lib/ansible/modules/extras/monitoring/rollbar_deployment.py

@@ -76,6 +76,7 @@ EXAMPLES = '''
                       comment='Test Deploy'
 '''
 
+import urllib
 
 def main():