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 "Add unit tests for generic/shell.py"
Merge "Fix auth_token middleware test invalid cross-device link issue"