SessionClient is subclassed from keystoneauth LegacyJsonAdapter.
LegacyJsonAdapter does not set the Content-Type explicitly
and results in decodeing issues in some cases.

Change-Id: Idf23022b394607c332490331fc4b216de6ff1313
Story: 2005237
Task: 30027
(cherry picked from commit bd33e310e09339a21097c66d4022538f6bcbad2f)

Decode before checking for py3 compatibility.

Change-Id: Ic62ebc385146ab1406dd64384044d92be8171052
Related-Bug: #1695144

In heatclient, some unit tests still use mox3,
which will make the test speed much slow, so I decide to remove it.
The modify file: heatclient/tests/unit/test_common_http.py

Change-Id: I220fabedb8e9fcc8eeea9d5e98b3ddeed68f8a43
Implements: bp remove-mox3-in-heatclient

We can initialize the 'mox' of module mox3 in __init__.py,
then in these files that have modified, we only have
'import mox' other than 'from mox3 import mox', which can
make the code smaller and clear.

Change-Id: Ic09597a7205eed47bd3cff03d1e7bc78744e52d4

According to the rule in http://docs.openstack.org/developer/hacking/#imports
I modify some irregular import format in heatclinet.

Change-Id: I0200ddad88ee833d7de9d6df2c1519e4f4560db7

SessionClient can not json serialize TemplateFiles object.
We should do them explictly.

Change-Id: Ia67562ae9a13c0975cb5c39532c0dc413d82c4c3
Closes-Bug: #1589519

move heatclient to keystoneauth as keystoneclient's auth session,
plugins and adapter code has been deprecated [1].

[1] http://docs.openstack.org/releasenotes/python-keystoneclient/mitaka.html#deprecation-notes

Change-Id: Iedd7ceb97d39ab3ecccf8786aad8b5f45d15175e

This allows redirects to use fully qualified location
from response header and removes the check to prohibit
redirects to different project(required for super admin
actions).

Change-Id: I46876189e96375922c4f0bf30452b7c4980fe39c