Do not try to call decode() on a text string

This fixes a call to 'isinstance' that only worked on Python2.

Closes-Bug: #1265879
Change-Id: I886da95f1ad2a8314de92be8aecb354ee3124e6d
Rename using-api.rst to using-api-v2.rst

Renaming file for consistency, since using-api-v3.rst is being written
there: https://review.openstack.org/#/c/63408

Minor changes have been made to indicate that the file documents the
keystone v2 API.

Change-Id: I694b658a8b59d21615af5d88edc0f7b394ebbe7b
Partial-Bug: #1260527
Add unit tests for generic/shell.py

blueprint generic-shell-unittest
Change-Id: I234c58d6e0dfa6402633f5f4f2149e7b1b9d36f2
Fix auth_token middleware test invalid cross-device link issue

Fixes path of temporary files, containing token revocation lists,
which weren't in the appropriate directory. File renaming now works
properly since source and destination files are in the same directory,
and therefore on the same partition.

Added to .gitignore temporary files generated during tests, that are
not being removed at the end of test.

Change-Id: I21ff81419313f4205ebe552556e27b86135fd096
Closes-Bug: #1265190
Merge "Rename using-api.rst to using-api-v2.rst"
Merge "Do not try to call decode() on a text string"
Merge "Add unit tests for generic/shell.py"
Merge "Fix auth_token middleware test invalid cross-device link issue"