Fixes #5467, #5494: Removes reliance on external RVM module and switches to single user install.

Removes the reliance on an external RVM module to allow installation as
the devel deployment user. Switches to using the 'vcsrepo' puppet module
to alleviate issues with switching directories when cloning. Lastly,
adds user creation and sets the user password to 'changeme' for all
devel deployments.