added waffle as the way to interact with s3 buckets

mix.exs

@@ -85,7 +85,13 @@ defmodule Mixer.MixProject do
       {:gettext, "~> 1.0"},
       {:jason, "~> 1.2"},
       {:dns_cluster, "~> 0.2.0"},
-      {:bandit, "~> 1.5"}
+      {:bandit, "~> 1.5"},
+      {:waffle, "~> 1.1.10"},
+      {:waffle_ecto, "~> 0.0"},
+      {:ex_aws, "~> 2.1.2"},
+      {:ex_aws_s3, "~> 2.0"},
+      {:hackney, "~> 1.9"},
+      {:sweet_xml, "~> 0.6"}
     ]
   end