There are some common methods in cliutils we can use in ceilometerclient: arg, env, unauthenticated, isunauthenticated. + Replaces utils.env to add alias env from cliutils. + Removes unused methods in utils: env To use methods from clituils. partially implements blueprint common-client-library-2 Change-Id: I295cc80635ed15c91e2832acb315e9deede09516