rbenv plugin now properly finds homebrew-installed rbenv (fixes #878)

plugins/rbenv/rbenv.plugin.zsh

@@ -4,6 +4,17 @@ for rbenvdir in "$HOME/.rbenv" "/usr/local/rbenv" "/opt/rbenv" ; do
     FOUND_RBENV=1
     export RBENV_ROOT=$rbenvdir
     export PATH=${rbenvdir}/bin:$PATH
+  fi
+done
+unset rbenvdir
+
+# Check for homebrew rbenv (installed directly in /usr/local/bin)
+if [ -f /usr/local/bin/rbenv -a $FOUND_RBENV -eq 0 ] ; then
+  FOUND_RBENV=1
+fi
+
+if [ $FOUND_RBENV -eq 1 ] ; then
+
   eval "$(rbenv init -)"
 
   alias rubies="rbenv versions"
@@ -33,11 +44,8 @@ for rbenvdir in "$HOME/.rbenv" "/usr/local/rbenv" "/opt/rbenv" ; do
       echo "$(current_ruby)"
     fi
   }
-  fi
-done
-unset rbenvdir
 
-if [ $FOUND_RBENV -eq 0 ] ; then
+else
   alias rubies='ruby -v'
   function gemsets() { echo 'not supported' }
   function rbenv_prompt_info() { echo "system: $(ruby -v | cut -f-2 -d ' ')" }