Specify a proper Ubuntu 16.04 box
Specify a proper Ubuntu 16.04 box

Specify a proper Ubuntu 16.04 box for VirtualBox provider in generic Xenial environment

Signed-off-by: Scott Lowe <4438a3189c2e58cebd81dd6bb6e49e12f5ad0fd6@scottlowe.org>

lowescott/learning-tools,lowescott/learning-tools,lowescott/learning-tools,lowescott/learning-tools