Fix user add task, add change password task

lib/mix/tasks/clacks/user.ex

@@ -12,7 +12,11 @@ defmodule Mix.Tasks.Clacks.User do
     {:ok, public_key_pem} = Keys.public_key_pem(public)
 
     changeset =
-      User.changeset(%User{}, %{username: username, private_key: pem, password: password})
+      User.registration_changeset(%User{}, %{
+        username: username,
+        private_key: pem,
+        password: password
+      })
 
     # start the app so the DB connection is established
     Mix.Task.run("app.start")
@@ -41,4 +45,21 @@ defmodule Mix.Tasks.Clacks.User do
 
     IO.puts("User #{username} successfully created")
   end
+
+  @shortdoc "Changes the given user's password"
+  def run(["change_password", username]) do
+    case User.get_by_username(username) do
+      nil ->
+        IO.puts("No user found with username '#{username}'")
+
+      user ->
+        password = IO.gets("Password: ") |> String.trim()
+
+        changeset = User.change_password_changeset(user, %{password: password})
+
+        {:ok, user} = Repo.update(changeset)
+
+        IO.puts("Password updated")
+    end
+  end
 end