Release 0.1.3

• Optimized fry rubies, before it was slowed down by the amount of
  rubies you had installed.
• Switch from PATH to fish_user_paths, this allows further control
  and visibility into your paths. You might not want to have the ruby
  path very first etc.
• Add config option for prepend path. In case you would like to have
  identical behaviour to the previous implementation (if you are using
  fish_user_paths for something).
• Introduce fry env that is a helper function to output a POSIX
  compatible PATH export.
• Rubinius gems path was moved in front of the ruby path