Fix installation problems for mac

README.md

@@ -93,7 +93,7 @@ Advanced images optimizer
 ```shell
 brew install exiftool imagemagick optipng libjpeg gifsicle
 
-formulas='pngout.rb  defluff.rb cryopng.rb imgo.rb'
+formulas='pngrewrite.rb pngout.rb  defluff.rb cryopng.rb imgo.rb'
 for package in $formulas
 do
   brew install "https://raw.github.com/imgo/imgo-tools/master/Formula/"$package