[ticket/11726] Don't run lint tests on Travis on postgres

PHPBB3-11726
Merge remote-tracking branch 'EXreaction/ticket/11726' into develop-olympus

* EXreaction/ticket/11726:
  [ticket/11726] Don't run lint tests on Travis on postgres
Merge branch 'develop-olympus' into develop

* develop-olympus:
  [ticket/11726] Don't run lint tests on Travis on postgres