Test for membership should be 'not in'

Enabled check for PEP8 issue E713.

Change-Id: Id41f5f19796a7af8cf4cb52dd7afc2e6ec1ccbc4
Remove 'node' parameter from the validate() methods

The node parameter is redundant since the node object is an attribute
of the task object.

Closes-Bug: #1312632
Change-Id: Ia4193ea561a31e54754049d9964c6c9021474caf
Merge "Test for membership should be 'not in'"
Merge "Remove 'node' parameter from the validate() methods"