Update to Elixir master

Author: José Valim

test/mix/tasks_test.exs

@@ -55,7 +55,7 @@ defmodule Mix.TasksTest do
     in_tmp "my_run_app", fn ->
       app_with_dynamo_deps_path
 
-      output = System.cmd %b{mix run "IO.inspect HelloRouter.__info__(:module)"}
+      output = System.cmd %b{mix run -e "IO.inspect HelloRouter.__info__(:module)"}
       assert output =~ %r(HelloRouter)
 
       # TODO: Get rid of this