Add ex_doc

mix.exs

@@ -42,6 +42,7 @@ defmodule Arc.Mixfile do
     [
       {:ex_aws, "~> 1.0.0-rc.1", optional: true},
       {:mock, "~> 0.1.1", only: :test},
+      {:ex_doc, "~> 0.14", only: :dev},
 
       # If using Amazon S3:
       {:hackney, "~> 1.5", optional: true},

mix.lock

@@ -1,5 +1,7 @@
 %{"certifi": {:hex, :certifi, "0.4.0", "a7966efb868b179023618d29a407548f70c52466bf1849b9e8ebd0e34b7ea11f", [:rebar3], []},
+  "earmark": {:hex, :earmark, "1.0.1", "2c2cd903bfdc3de3f189bd9a8d4569a075b88a8981ded9a0d95672f6e2b63141", [:mix], []},
   "ex_aws": {:hex, :ex_aws, "1.0.0-rc.1", "1fc21b65686892fe24ea0ff699e347c30ab538f69f9ed15b6cb488cc6e1900d9", [:mix], [{:gen_stage, "~> 0.5.0", [hex: :gen_stage, optional: false]}, {:hackney, "~> 1.5", [hex: :hackney, optional: true]}, {:jsx, "~> 2.8", [hex: :jsx, optional: true]}, {:poison, "~> 1.2 or ~> 2.0", [hex: :poison, optional: true]}, {:sweet_xml, "~> 0.5", [hex: :sweet_xml, optional: true]}]},
+  "ex_doc": {:hex, :ex_doc, "0.14.1", "bfed8d4e93c755e2b150be925ad2cfa6af7c3bfcacc3b609f45f6048c9d623d6", [:mix], [{:earmark, "~> 1.0", [hex: :earmark, optional: false]}]},
   "gen_stage": {:hex, :gen_stage, "0.5.0", "758068f3a81286e342a609d668e9624714c2e4d43cc26699ead04d1680fde6c6", [:mix], []},
   "hackney": {:hex, :hackney, "1.6.1", "ddd22d42db2b50e6a155439c8811b8f6df61a4395de10509714ad2751c6da817", [:rebar3], [{:certifi, "0.4.0", [hex: :certifi, optional: false]}, {:idna, "1.2.0", [hex: :idna, optional: false]}, {:metrics, "1.0.1", [hex: :metrics, optional: false]}, {:mimerl, "1.0.2", [hex: :mimerl, optional: false]}, {:ssl_verify_fun, "1.1.0", [hex: :ssl_verify_fun, optional: false]}]},
   "httpoison": {:hex, :httpoison, "0.9.1", "6c2b4eaf2588a6f3ef29663d28c992531ca3f0bc832a97e0359bc822978e1c5d", [:mix], [{:hackney, "~> 1.6.0", [hex: :hackney, optional: false]}]},