Change the list webhooks interface and schema to specify a list rather than a dict
Change mock webhooks to return a list rather than a dictionary
Change cass model to return a list of webhooks instead of dict
Fix the rest endpoint expectation that webhooks be a dictionary
Fix some docstrings
Fix lint
Change schema so that webhooks (not a list of webhooks) are the item in webhook lists (thanks @manishtomar)
Merge pull request #405 from rackerlabs/change-list-webhooks-format-in-model

Change list webhooks format in model