FIX: actually optimize the image!

app/models/optimized_image.rb

@@ -153,7 +153,7 @@ class OptimizedImage < ActiveRecord::Base
 
     return false if $?.exitstatus != 0
 
-    ImageOptim.new.optimize_image(to) rescue nil
+    ImageOptim.new.optimize_image!(to) rescue nil
     true
   end
 

lib/letter_avatar.rb

@@ -78,7 +78,7 @@ class LetterAvatar
 
       `convert #{instructions.join(" ")}`
 
-      ImageOptim.new.optimize_image(filename) rescue nil
+      ImageOptim.new.optimize_image!(filename) rescue nil
 
       filename
     end