Extend status_description column in Clusters tables

Convert column type to
 * Text for psql - unlimited size
 * LongText for mysql - max size 2^32

Also fixed template for autogenerated migrations: added a blank line to
avoid pep8 violation.

Closes-Bug: #1338933
Change-Id: Ie4c4f57aeb7ff03aa7f6077629f6463a136f8f4b
Switched Sahara unit tests base class to oslotest

Implements blueprint: oslotest

Change-Id: Ied0ff893b329b3f1fbe01518f9d77b33d734b9c1
Fix hardcoded username(ec2-user) for heat-engine

heat-engine pass a username associated with the image
to heat template's "admin_user" field

Change-Id: I8d3b218de668d0003bf3277826d85857fc297bc3
Closes-Bug: 1336525
Fixed configuring instances for Vanilla 2.0

Fixed configuring instances and starting services using threaded
SSH command for Vanilla Hadoop 2.0.

Change-Id: I2357f72762a3a73adb42208fe64a835cffa5716b
Closes-bug: #1324289
Add vanilla plugin with Hadoop 2.4.0

Hadoop 2.4.0 fails on pig job
https://bugs.launchpad.net/sahara/+bug/1340738

partially implements blueprint add-vanilla-2-hadoop-2-4-0

Change-Id: Iaa36dcf4fbb7c5162ca768bae03cc7faeb988a6b
Fix scaling cluster Vanilla for Hadoop 2.3

Fixed scaling cluster without resourcemanager
for Vanilla Plugin for Hadoop 2.3

Change-Id: I5ba97b3d48f2c395db19a44ff7b37f234fe0b719
Closes-bug: #1339138
Update oslo-incubator log module

Changes -
 * Ability to customize default_log_levels for each project
 * Python 3: enable tests/unit/test_log.py
 * Move `mask_password` to strutils
 * update new requests logger to default WARN
 * Remove extra whitespace
 * Use oslo.messaging to publish log errors
 * pep8: fixed multiple violations
 * Fix common.log.ContextFormatter for Python 3
 * Mask passwords included without quotes at the ends of commands
 * Fixes a simple spelling mistake

Change-Id: I485e76890aa1a93415399c9457d6d87c7c5ed1c9
Update oslo-incubator fileutils module

Changes -
 * file_open: fixed docstring to refer to open() instead of file()

Change-Id: I7d3fec1fafe548ad87973d33d052ea7cc79aeb59
Update oslo-incubator lockutils module

Changes -
 * Don't import fcntl on Windows
 * pep8: fixed multiple violations
 * fixed typos found by RETF rules

Change-Id: I3c3504fe705ee2d91414323217f7185a7a695e43
Update oslo-incubator config.generator module

Changes -
 * generator: remove unused param, small clean up

Change-Id: I74e54cd684bc2a363d358064890f1e13f9ab5acc
Update oslo-incubator context module

Changes -
 * Add a RequestContext.from_dict method

Change-Id: I1781661a93ce533cd2b609661b3c505ddc9cb730
Update oslo-incubator loopingcall module

Changes -
 * Changes calcuation of variable delay
 * Use timestamp in loopingcall
 * Log the function name of looping call

Change-Id: Iebe6913d731b4cee105c11abf7007ec13f0f5787
Merge "Add vanilla plugin with Hadoop 2.4.0"
Merge "Update oslo-incubator log module"
Renamed Pending to PENDING
fixes bug 1329526

Change-Id: I53750cd9bf23df06678d555e5c1fecfcc98edca3
Merge "Fix scaling cluster Vanilla for Hadoop 2.3"
Revert "Fix use of novaclient.exceptions.NotFound"

It was fixed in nova client now, so, we need to revert this fix too.
https://github.com/openstack/python-novaclient/releases/tag/2.18.1

https://github.com/openstack/python-novaclient/compare/2.18.0...2.18.1

This reverts commit 29026c88a1a0528ca9a73a941cb9d49015d83342.

Change-Id: I79503e4c33959ae43d5f2a4daf0d383f1aecd1b4
Merge "Revert "Fix use of novaclient.exceptions.NotFound""
Merge "Update oslo-incubator fileutils module"
Merge "Update oslo-incubator lockutils module"