Added earmark and validate Elixir package dependencies

mix.exs

@@ -59,7 +59,8 @@ defmodule Sukaato.MixProject do
       {:dns_cluster, "~> 0.1.1"},
       {:bandit, "~> 1.5"},
       {:toml, "~> 0.7.0"},
-      {:earmark, "~> 1.4"}
+      {:earmark, "~> 1.4"},
+      {:validate, "~> 1.3"}
     ]
   end