VMware: spawn refactor - phase 1 - test for spawn

Adding a test case for spawn to ensure all the correct methods are
called.  This test will get further fleshed out with explicit
assertions of behavior along with additional factoring pertaining to
image handling and manipulation.

partial blueprint vmware-spawn-refactor

Change-Id: Ia137f1ea4b9fa43741cdd7d610831da8e5474d62
Merge "VMware: spawn refactor - phase 1 - test for spawn"