Move test .conf files to keystone/tests/config_files

Move the test configuration files to an isolated directory. This
allows for less clutter in the keystone/tests directory and keeps
the configuration data a bit more isolated from the test cases
themselves.

Change-Id: I054393b968824a0e3c31fd227d7b09e9c14c764b
Merge "Move test .conf files to keystone/tests/config_files"