[rvm] install ruby rvm

#curl -L https://get.rvm.io | bash -s stable --ruby


Installation of RVM in /usr/local/rvm/ is almost complete:

* First you need to add all users that will be using rvm to 'rvm' group,
and logout - login again, anyone using rvm will be operating with `umask u=rwx,g=rwx,o=rx`.

* To start using RVM you need to run `source /etc/profile.d/rvm.sh`
in all your open shell windows, in rare cases you need to reopen all shell windows.


#gpasswd -a root rvm