Extend evil-rails ex commands to cover all projectile-rails commands

I've just made an extension of the main evil-rails.el file to include all projectile-rails commands with sensible ex-commands.

- R prefixed are general projectile-rails commands, e.g. :Rconsole, :Rserver, :Rrake, etc. I kept untouched find commands because it could disrupt ex-command workflow from the original version. I'd like to propose RF prefix but needs further discussion.
- RC prefixed are find-current specific projectile-rails commands, e.g. :RCview, :RCmodel.
- RG prefixed are goto specific projectile-rails commands, e.g. :RGroutes, :RGschema.

Since :A ex command is about projectile in general, it's not related directly to evil-rails but left untouched.