Delete unused MiqSystem.swapinfo.
Delete unused MiqSystem.swapinfo.

We need to convert these runcmd calls to use AwesomeSpawn to fix quoting issues.
Since swapinfo isn't called and is lacking tests, let's delete this and add it
when we know what we need.

Preliminary for Postgresql 9.4 support:
https://trello.com/c/Mk4DhnCW

aljesusg/manageiq-gems-pending,rsevilla87/manageiq-gems-pending,rsevilla87/manageiq-gems-pending,aljesusg/manageiq-gems-pending