mix escriptize: Only include .beam and .app files from ebin.

Fixes #768.

Author: alexrp

lib/mix/lib/mix/tasks/escriptize.ex

@@ -117,7 +117,7 @@ defmodule Mix.Tasks.Escriptize do
   end
 
   defp get_files(dir) do
-    lc f inlist Path.wildcard("#{dir}/**/*") do
+    lc f inlist Path.wildcard("#{dir}/**/*.{app,beam}") do
       { binary_to_list(Path.basename(f)), File.read!(f) }
     end
   end