Don't forget mix.exs

mix.exs

@@ -0,0 +1,20 @@
+defmodule Geef.Mixfile do
+  use Mix.Project
+
+  def project do
+    [ app: :geef,
+      version: "0.0.1",
+      deps: deps ]
+  end
+
+  # Configuration for the OTP application
+  def application do
+    []
+  end
+
+  # Returns the list of dependencies in the format:
+  # { :foobar, "0.1", git: "https://github.com/elixir-lang/foobar.git" }
+  defp deps do
+    []
+  end
+end