Solum M1 argparse-based Python CLI

* Implements text parsing only, no REST communications
* Implements Application create, delete and list
* Implements Assembly create, delete and list
* Includes some very basic unit tests (expand when REST is added)

Partially implements: blueprint solum-minimal-cli

Change-Id: I0b1431ffb84b0c6ee71640483669bf55401dc81b