CDAP-506: Allow CLI completers to access context

I have changed version of common.cli from 0.1.0 to 0.2.0-SNAPSHOT, because this changes require 0.2.0-SNAPSHOT version of common.cli. @jwang47 Is this right choice?
If not, let's merge this and refactor it later, since we only have two or three completers that need to access the context.