Add module to create supply

lib/inmana/supplies/create.ex

@@ -0,0 +1,14 @@
+defmodule Inmana.Supplies.Create do
+    alias Inmana.{Repo, Supply}
+
+    def call(params) do
+        params
+        |> Supply.changeset()
+        |> Repo.insert()
+        |> handle_insert()
+    end
+
+    defp handle_insert({:ok, %Supply{}} = result), do: result
+
+    defp handle_insert({:error, result}), do: {:error, %{result: result, status: :bad_request}}
+end