There are some common methods in cliutils we can use in novaclient:
arg, env, unauthenticated, isunauthenticated.
+ Replaces utils.env to add alias env from cliutils.
+ Replaces utils.arg to add alias arg from cliutils.
+ Removes unused methods: add_arg, unauthenticated, isunauthenticated
To use methods from clituils.
Related to blueprint common-client-library-2
Change-Id: Ic7c132c37d6a91cf3eae55530300efd153c31903