Replace gcloud with python

docs/iam-usage.rst

@@ -41,10 +41,8 @@ Roles
 Roles represent bundles of permissions that can be added to members.
 For a complete list of roles available on a resource run::
 
-    ``gcloud iam list-grantable-roles //fully/qualified/resource/path``
+    >>> resource.get_roles()
 
-
-<<<<<<< Updated upstream
 An ``iam.Role`` object has a name, title, and description
 
 - ``name``: the canonical name of a role. This will be the value
@@ -149,10 +147,10 @@ ffdFADFdsgfsjrsHTY
 >>> etag
 ffdFADFdsgfsjrsHTY
 
-``query_grantable_roles()`` returns a list of ``iam.Role`` objects that represent roles (and their associated metadata)
+``get_roles()`` returns a list of ``iam.Role`` objects that represent roles (and their associated metadata)
 which can be granted on the specified resource
 
->>> resource.query_grantable_roles()
+>>> resource.get_roles()
 [<Role: 'roles/owner'>, <Role: 'roles/editor'>, <Role: 'roles/reader'>]