text: Title: test_messages, maybe a mistake, maybe my error
  Body: Current block is:
  ```
  def test_messages(client):
      """Ensure that user can post messages"""
      login(client, app.config["USERNAME"], app.config["PASSWORD"])
      rv = client.post(
          "/add",
          data=dict(title="<Hello>", text="<strong>HTML</strong> allowed here"),
          follow_redirects=True,
      )
      assert b"No entries here so far" not in rv.data
      assert b"&lt;Hello&gt;" in rv.data
      assert b"<strong>HTML</strong> allowed here" in rv.data
  ```
  But this never passes the final test.
  
  I replaced the first of the 3 asserts with 
  `assert b"New entry was successfully posted" in rv.data`
  
  Which then passes