Add Fish configs for RVM

fish/conf.d/rvm.fish

@@ -0,0 +1,3 @@
+if which rvm >/dev/null
+    rvm current
+end

fish/functions/rvm.fish

@@ -0,0 +1,42 @@
+function rvm --description='Ruby enVironment Manager'
+  # run RVM and capture the resulting environment
+  set --local env_file (mktemp -t rvm.fish.XXXXXXXXXX)
+
+  # This finds where RVM's root directory is and sources scripts/rvm from within it.  Then loads RVM in a clean environment and dumps the environment variables it generates out for us to use.
+  bash -c 'PATH=$GEM_HOME/bin:$PATH;RVMA=$(which rvm);RVMB=$(whereis rvm | sed "s/rvm://");source $(if test $RVMA;then echo $RVMA | sed "s/\/bin\//\/scripts\//";elif test $RVMB; then echo $RVMB | sed "s/rvm/rvm\/scripts\/rvm/"; else echo ~/.rvm/scripts/rvm; fi); rvm "$@"; status=$?; env > "$0"; exit $status' $env_file $argv
+
+  # apply rvm_* and *PATH variables from the captured environment
+  and eval (grep -E '^rvm|^PATH|^GEM_PATH|^GEM_HOME' $env_file | grep -v '_clr=' | sed '/^[^=]*PATH/s/:/" "/g; s/^/set -xg /; s/=/ "/; s/$/" ;/; s/(//; s/)//')
+
+  # needed under fish >= 2.2.0
+  and set -xg GEM_PATH (echo $GEM_PATH | sed 's/ /:/g')
+
+  # clean up
+  rm -f $env_file
+end
+
+function __handle_rvmrc_stuff --on-variable PWD
+  # Source a .rvmrc file in a directory after changing to it, if it exists.
+  # To disable this feature, set rvm_project_rvmrc=0 in $HOME/.rvmrc
+  if test "$rvm_project_rvmrc" != 0
+    set -l cwd $PWD
+    while true
+      if contains $cwd "" $HOME "/"
+        if test "$rvm_project_rvmrc_default" = 1
+          rvm default 1>/dev/null 2>&1
+        end
+        break
+      else
+        if test -e .rvmrc -o -e .ruby-version -o -e .ruby-gemset -o -e Gemfile
+          eval "rvm reload" > /dev/null
+          eval "rvm rvmrc load" >/dev/null
+          break
+        else
+          set cwd (dirname "$cwd")
+        end
+      end
+    end
+
+    set -e cwd
+  end
+end