releasenotes: add notes for Mitaka cycle

Change-Id: I535fa5aa2e052027cc4fd52611cf39fb12806de9

releasenotes/notes/catch_403-237b79f33ab3364f.yaml

@@ -0,0 +1,3 @@
+---
+fixes:
+  - Catch HTTP 403 responses (not authorized requests) in openstack provider.

releasenotes/notes/ipv6_brackets-7a453aea5e091855.yaml

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+---
+features:
+  - Utility to handle IPv6 address brackets with normalize_ip_for_uri
+    is a function that help us to add brackets to IPv6 addresses
+    when missing. The function moved to puppetlabs-stdlib but is not in latest release
+    yet. Once it's done, we'll probably drop this function so our modules will use stdlib.

releasenotes/notes/more_db_options-d96316ae4eb5a78c.yaml

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+---
+features:
+  - Add an "extra" hash parameter to os_database_connection that allows to extend
+    the database uri configuration.

releasenotes/notes/retry_client-b8a0e1f9ff679281.yaml

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+---
+fixes:
+  - Add retries to the openstack command.
+    Increase command timeout to 20s and request timeout to 60s
+    and sleep 3s between retries. Do not retry non-idempotent actions.
+    This is a more robust implementation that will prevent failures in case
+    of Keystone API failures during a deployment.