Remove RAX-specific auth in troveclient

Author: Swapnil Kulkarni <swapnilkulkarni2608@gmail.com>
Co-Authored-By: Nikhil Manchanda <SlickNik@gmail.com>
Co-Authored-By: Craig Vyvial <cp16net@gmail.com>

Change-Id: I250777890a1f5240c5f14290cf02eb5a7b34b434
Closes-Bug: #966329
Merge "Remove RAX-specific auth in troveclient"