Remove versionutils use in cli framework

The oslo-incubator version utils module requires oslo log to be pulled
in. This causes conflicts with tempest's use of oslo.log, so for the
time being this commit removes the uses of versionutils from the
library.
Add missing log_format definition

As part of shrinking the base test class file down to just the core
functionality the definition for the logging fixture log format was
accidently removed. This causes any test based on the test class to
fail during setUp. This commit fixes the oversight by adding it back.
Remove admin param from client method definitions

This commit removes the admin kwarg from the client methods in the
CLIClientBase class. The admin argument was a leftover from tempest
but it doesn't have a place in the new class, because it just takes
in credentials as args. So admin can be specified by just initializing
the class using admin credentials.
Add the cli_dir argument to nova-mange's execute call

This commit adds a missing cli_dir argument to the nova-manage execute
call. Without this if nova-manage were installed somewhere besides
/usr/bin using the nova_manage method would fail because it couldn't
find the binary.