title: Django: send notifications at user based on database change
body: <p>I have 3 database tables:</p>
  <ul>
  <li>users (stores info about users e.g. email, name)</li>
  <li>metadata (stores data)</li>
  <li>activity (stores changes made to users/metadata tables)</li>
  </ul>
  <p>I want to achieve the following:</p>
  <ul>
  <li>to store any change into the activity table (e.g. new user is created, a user updates the metadata table)</li>
  <li>to send notifications to users whenever a change into the users/metadata tables happens.</li>
  </ul>
  <p>What are the libraries/method that I could use in order to achieve the desired functionalities? Thank you!</p>