Remove unneeded required_one_of for openstack

We're being too strict - there is a third possibility, which is that a
user will have defined the OS_* environment variables and expect them to
pass through.

Conflicts:
	lib/ansible/module_utils/openstack.py
	lib/ansible/utils/module_docs_fragments/openstack.py
	v2/ansible/module_utils/openstack.py

lib/ansible/module_utils/openstack.py

@@ -91,9 +91,6 @@ def openstack_full_argument_spec(**kwargs):
 
 def openstack_module_kwargs(**kwargs):
     ret = dict(
-        required_one_of=[
-            ['cloud', 'auth'],
-        ],
         mutually_exclusive=[
             ['auth', 'auth_token'],
             ['auth_plugin', 'auth_token'],

lib/ansible/utils/module_docs_fragments/openstack.py

@@ -32,7 +32,8 @@ options:
         I(auth_url), I(username), I(password), I(project_name) and any
         information about domains if the cloud supports them. For other plugins,
         this param will need to contain whatever parameters that auth plugin
-        requires. This parameter is not needed if a named cloud is provided.
+        requires. This parameter is not needed if a named cloud is provided or
+        OpenStack OS_* environment variables are present.
     required: false
   auth_plugin:
     description:

v2/ansible/module_utils/openstack.py

@@ -67,3 +67,35 @@ def openstack_find_nova_addresses(addresses, ext_tag, key_name=None):
                     ret.append(interface_spec['addr'])
     return ret
 
+def openstack_full_argument_spec(**kwargs):
+    spec = dict(
+        cloud=dict(default=None),
+        auth_type=dict(default=None),
+        auth=dict(default=None),
+        region_name=dict(default=None),
+        availability_zone=dict(default=None),
+        verify=dict(default=True, aliases=['validate_certs']),
+        cacert=dict(default=None),
+        cert=dict(default=None),
+        key=dict(default=None),
+        wait=dict(default=True, type='bool'),
+        timeout=dict(default=180, type='int'),
+        api_timeout=dict(default=None, type='int'),
+        endpoint_type=dict(
+            default='public', choices=['public', 'internal', 'admin']
+        )
+    )
+    spec.update(kwargs)
+    return spec
+
+
+def openstack_module_kwargs(**kwargs):
+    ret = {}
+    for key in ('mutually_exclusive', 'required_together', 'required_one_of'):
+        if key in kwargs:
+            if key in ret:
+                ret[key].extend(kwargs[key])
+            else:
+                ret[key] = kwargs[key]
+
+    return ret