`TestPing` from `vmspec` fails on Ubuntu Minimal images

``` <testcase name="TestPing" classname="" time="0.000"> <failure message="Failed"><![CDATA[ vmspec_test.go:110: error pinging google.com on nic ens5, result: , err: exec: "ping": executable file not found in $PATH]]> </failure> ``` This one's pretty easy to explain, it's simply that `iputils` is not installed in `minimal` images by default 😄. So we have two choices here: 1. Skip this test on minimal images 2. Still run the test but install `iputils` via `CommandContext` as part of the test set up