Create separate security group for Inception VM

Currently the Inception VM is assigned the default security group, which is problematic when we start wanting to open extra "inception VM specific" ports (like MOSH).

This PR creates a new security group named `#{bosh_name}-inception-vm` and assigns it to the inception VM instead of the `default` sg

It also enables the inception VM to be pinged.

It is currently a work in progress.