Various refactoring and typespec improvements

Signed-off-by: Thomas Citharel <tcit@tcit.fr>

lib/mobilizon/addresses/address.ex

@@ -57,7 +57,7 @@ defmodule Mobilizon.Addresses.Address do
   end
 
   @doc false
-  @spec changeset(t, map) :: Ecto.Changeset.t()
+  @spec changeset(t | Ecto.Schema.t(), map) :: Ecto.Changeset.t()
   def changeset(%__MODULE__{} = address, attrs) do
     address
     |> cast(attrs, @attrs)