[ticket/12147] Remove Travis CI notifications.

We don't want to get notifications for branches other people are working on.

PHPBB3-12147
Merge remote-tracking branch 'github-bantu/ticket/12147' into develop-olympus

* github-bantu/ticket/12147:
  [ticket/12147] Remove Travis CI notifications.
[ticket/12146] Added a missing # to inline css-style of <span>

PHPBB3-12146
Merge remote-tracking branch 'Crizz0/ticket/12146' into develop-olympus

* Crizz0/ticket/12146:
  [ticket/12146] Added a missing # to inline css-style of <span>