Enable Ocata Amulet Tests

- Add Zesty as a supported series to metadata.yaml.
- Turn on Xenial-Ocata Amulet test definitions.
- Sync charm helpers to get Juju 2.x amulet compatibility.
- Keeping Zesty-Ocata Amulet test definitions turned off until the
  metadata.yaml changes propagate to the charm store.

Change-Id: I4ddfc80ad9ab6e3bacc391b7acfba05ed032f4dc

src/metadata.yaml

@@ -12,6 +12,7 @@ tags:
   - openstack
 series:
   - xenial
+  - zesty
   - yakkety
 subordinate: false
 requires:

src/tests/gate-basic-xenial-ocata

@@ -0,0 +1,10 @@
+#!/usr/bin/env python
+
+"""Amulet tests on a basic manila deployment on xenial-ocata.
+"""
+
+from basic_deployment import ManilaBasicDeployment
+
+if __name__ == '__main__':
+    deployment = ManilaBasicDeployment(series='xenial')
+    deployment.run_tests()

src/tests/gate-basic-zesty-ocata

@@ -0,0 +1,10 @@
+#!/usr/bin/env python
+
+"""Amulet tests on a basic manila deployment on zesty-ocata.
+"""
+
+from basic_deployment import ManilaBasicDeployment
+
+if __name__ == '__main__':
+    deployment = ManilaBasicDeployment(series='zesty')
+    deployment.run_tests()