title: ARC (In Elixir app) won't upload to S3
body: <p>I'm having a problem configuring ARC to work in my app.  First, when I use the configuration as described below, the file is loaded into local storage.  If I add the line</p>
  
  <pre><code>def __storage, do: Arc.Storage.Local
  </code></pre>
  
  <p>to <code>uploader.ex</code>, I get an error -- not too informative: "something went wrong."  Also, when I try a direct upload, here is what happens:</p>
  
  <pre><code>iex(2)&gt; Avatar.store("/Users/carlson/Downloads/jupiter.jpg")
  {:ok, "jupiter.jpg"}
  </code></pre>
  
  <p>However, when I check my S3 bucket, I find only a few old items.  And nothing is added to local storage</p>
  
  <ol>
  <li><p>CONFIG</p>
  
  <h1>files: config.dev, config.prod</h1>
  
  <pre><code>config :arc,
   storage: Arc.Storage.S3,
   bucket: "noteimages"
  
  config :ex_aws,
   access_key_id: System.get_env("AWS_ACCESS_KEY_ID"),
   secret_access_key: System.get_env("AWS_SECRET_ACCESS_KEY")
  </code></pre></li>
  <li><p>MIX.EXS</p>
  
  <h1>file: mix.exs:</h1>
  
  <pre><code>defp deps do
    [{:phoenix, "~&gt; 1.2.1"},
     {:phoenix_pubsub, "~&gt; 1.0"},
     {:phoenix_ecto, "~&gt; 3.0"},
     {:postgrex, "&gt;= 0.0.0"},
     {:phoenix_html, "~&gt; 2.6"},
     {:phoenix_live_reload, "~&gt; 1.0", only: :dev},
     {:gettext, "~&gt; 0.11"},
     {:cowboy, "~&gt; 1.0"},
     {:comeonin, "~&gt; 2.0"},
     {:mnemonix, "~&gt; 0.2.0"},
     {:timex, "~&gt;3.0"},
     {:timex_ecto, "~&gt; 3.0"},
     {:benchfella, "~&gt; 0.3.2"},
     {:json, "~&gt; 1.0"},
     {:joken, "~&gt; 1.1"},
     {:arc, "~&gt; 0.8.0"},
     {:arc_ecto, "~&gt; 0.4", override: true},
     {:shared, in_umbrella: true},
     {:ex_aws, "~&gt; 1.1"},
     {:poison, "~&gt; 2.0"},
     {:httpoison, "~&gt; 0.11"},
     {:hackney, "~&gt; 1.6"}]
  end
  </code></pre></li>
  <li><p>S3 Bucket policy</p>
  
  <pre><code>{  
     "Version":"2012-10-17",
     "Id":"Policy1493266128611",
     "Statement":[  
        {  
           "Sid":"Stmt1493266101437",
           "Effect":"Allow",
           "Principal":{  
              "AWS":"*"
           },
           "Action":"s3:GetObject",
           "Resource":"arn:aws:s3:::noteimages/*"
        }
     ]
  }
  </code></pre></li>
  </ol>