refactor buyer and insured and add more policy types

mix.exs

@@ -78,7 +78,13 @@ defmodule PolicyService.MixProject do
       "ecto.setup": ["ecto.create", "ecto.migrate", "run priv/repo/seeds.exs"],
       "ecto.reset": ["ecto.drop", "ecto.setup"],
       test: ["ecto.create --quiet", "ecto.migrate --quiet", "test"],
-      precommit: ["compile --warnings-as-errors", "deps.unlock --unused", "format", "test"]
+      precommit: [
+        "compile --warnings-as-errors",
+        "deps.unlock --unused",
+        "dialyzer",
+        "format",
+        "test"
+      ]
     ]
   end
 end