Add 'token' option for easy token retrieval

Just do
fuel token

You can use this in manual curl requests:
curl '<api-url>' -H "X-Auth-Token: $(fuel token)"

DocImpact
Change-Id: I634160beedd347b90a249b073560483f33586b98

fuelclient/cli/actions/__init__.py

@@ -20,6 +20,7 @@ from fuelclient.cli.actions.deploy import DeployChangesAction
 from fuelclient.cli.actions.environment import EnvironmentAction
 from fuelclient.cli.actions.fact import DeploymentAction
 from fuelclient.cli.actions.fact import ProvisioningAction
+from fuelclient.cli.actions.token import TokenAction
 from fuelclient.cli.actions.health import HealthCheckAction
 from fuelclient.cli.actions.interrupt import ResetAction
 from fuelclient.cli.actions.interrupt import StopAction
@@ -55,7 +56,8 @@ actions_tuple = (
     PluginAction,
     NodeGroupAction,
     NotificationsAction,
-    NotifyAction
+    NotifyAction,
+    TokenAction
 )
 
 actions = dict(

fuelclient/cli/actions/token.py

@@ -0,0 +1,37 @@
+#    Copyright 2015 Mirantis, Inc.
+#
+#    Licensed under the Apache License, Version 2.0 (the "License"); you may
+#    not use this file except in compliance with the License. You may obtain
+#    a copy of the License at
+#
+#         http://www.apache.org/licenses/LICENSE-2.0
+#
+#    Unless required by applicable law or agreed to in writing, software
+#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+#    License for the specific language governing permissions and limitations
+#    under the License.
+
+import sys
+
+from fuelclient.cli.actions.base import Action
+from fuelclient.client import APIClient
+
+
+class TokenAction(Action):
+    """Return a valid keystone auth token
+    """
+    action_name = "token"
+
+    def __init__(self):
+        super(TokenAction, self).__init__()
+
+        self.args = []
+        self.flag_func_map = (
+            (None, self.get_token),
+        )
+
+    def get_token(self, params):
+        """Print out a valid Keystone auth token
+        """
+        sys.stdout.write(APIClient.auth_token)

fuelclient/tests/test_token_action.py

@@ -0,0 +1,37 @@
+# -*- coding: utf-8 -*-
+#
+#    Copyright 2015 Mirantis, Inc.
+#
+#    Licensed under the Apache License, Version 2.0 (the "License"); you may
+#    not use this file except in compliance with the License. You may obtain
+#    a copy of the License at
+#
+#         http://www.apache.org/licenses/LICENSE-2.0
+#
+#    Unless required by applicable law or agreed to in writing, software
+#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+#    License for the specific language governing permissions and limitations
+#    under the License.
+
+import io
+
+import mock
+
+from fuelclient.tests import base
+
+
+@mock.patch('fuelclient.client.requests')
+class TestPluginsActions(base.UnitTestCase):
+
+    @mock.patch('fuelclient.cli.actions.token.APIClient')
+    def test_token_action(self, mAPIClient, mrequests):
+        with mock.patch('sys.stdout', new=io.StringIO()) as mstdout:
+            token = u'token123'
+            mauth_token = mock.PropertyMock(return_value=token)
+            type(mAPIClient).auth_token = mauth_token
+
+            self.execute(['fuel', 'token'])
+
+            self.assertEqual(mauth_token.call_count, 1)
+            self.assertEqual(mstdout.getvalue(), token)