Some formatting, logic, and speedup improvements(only create the same regexes once).
Fix pylint errors, the `_rvm()` and `_do_rvm()`  were being given `runas` twice because of a badly constructed `command` string.
Merge pull request #6138 from s0undt3ch/hotfix/salt-modules-rvm-pylint

Fix the errors shown by pylint in the rvm module