Merge pull request elixir-lang#736 from bkoltai/bk_1_2_release

Change `1.2-dev` references to `1.2`

Author: ericmj

getting-started/mix-otp/dependencies-and-umbrella-apps.markdown

@@ -159,7 +159,7 @@ defmodule KVServer.Mixfile do
      config_path: "../../config/config.exs",
      deps_path: "../../deps",
      lockfile: "../../mix.lock",
-     elixir: "~> 1.2-dev",
+     elixir: "~> 1.2",
      build_embedded: Mix.env == :prod,
      start_permanent: Mix.env == :prod,
      deps: deps]