Implement CRUD operations for Identity Providers

Operations for:
    * adding Identity Provider
    * listing Identity Providers
    * showing Identity Provider
    * updating Identity Provider
    * deleting Identity Provider

Change-Id: I4557168309f93e4670116b5c3c0e29252ff0c40f
Implements: bp/add-openstackclient-federation-crud
Merge "Implement CRUD operations for Identity Providers"