Remove WSU SMTP as an MU Plugin for the platform

This is a very WSU specific plugin and should be kept external so
that anyone else using the platform does not have to account for it.

We'll be adding the real WSU SMTP plugin and activating it globally
on the platform instead
Remove WSU Fight Song MU Plugin

This has been moved to a globally activated plugin on the platform
in order to remove WSU specific messaging from the WSUWP Platform
Merge pull request #157 from washingtonstateuniversity/remove/wsu-plugins

[PR] Remove WSU specific plugins