Remove the "short circuit" check from chruby_use (issue #46).
Remove the "short circuit" check from chruby_use (issue #46).

* This ensures that if PATH, RUBYOPT, GEM_HOME or GEM_PATH are modified,
  a user can call `chruby X.Y.Z` a second time to reset the variables.

JeanMertz/chruby-fish,kbrock/chruby,ilikepi/chruby,rstacruz/chruby-fish,postmodern/chruby,kbrock/chruby,ngpestelos/chruby,postmodern/chruby,regularfry/chruby,ngpestelos/chruby,ilikepi/chruby,eunomie/chgo,rstacruz/chruby-fish,JeanMertz/chruby-fish,regularfry/chruby,eunomie/chgo