Images API v2.0 Upload Image File Tests

Implements upload image file tests:
 - renamed 'test_put_image.py' to 'test_upload_image_file.py'
 - added more test steps to improve test implementation
 - added new test scenarios in 'test_upload_image_file_negative.py' module

Depends on https://review.openstack.org/60812
 - this is a cloudcafe PR which has been merged already

Refactors the tests:
 - added tags.
 - removed the 'tearDownClass' method.
 - changed 'smoke' tag to 'positive' tag as discussed with the glance team.
 - improved data clean up as per review comment.

Change-Id: Id0bd3cf1d3e50136a613c0801153395838ea1193
Merge "Images API v2.0 Upload Image File Tests"