Fix env_cred AWS creation return value (#66)

Signed-off-by: Webster Mudge <[email protected]>

Author: wmudge

src/cdpy/environments.py

@@ -251,9 +251,9 @@ def delete_credential(self, name):
 
     def create_aws_credential(self, name, role, description, retries=3, delay=2):
         resp = self.sdk.call(
-            svc='environments', func='create_aws_credential', ret_error=True, squelch=[
-                Squelch(field='violations', value='Credential already exists with name',
-                        warning='Credential with this name already exists', default=None)],
+            svc='environments', func='create_aws_credential', ret_error=True, 
+            ret_field='credential', squelch=[Squelch(field='violations', value='Credential already exists with name',
+                warning='Credential with this name already exists', default=None)],
             credentialName=name,
             roleArn=role,
             description=description