[ticket/11580] Enable --no-interaction option on composer for travis

There is no interaction available on travis ;)

PHPBB3-11580
[ticket/11580] Enable prefer-source option (should error way less)

PHPBB3-11580
Merge remote-tracking branch 'nickvergessen/ticket/11580' into develop-olympus

* nickvergessen/ticket/11580:
  [ticket/11580] Enable prefer-source option (should error way less)
  [ticket/11580] Enable --no-interaction option on composer for travis
Merge branch 'develop-olympus' into develop

* develop-olympus:
  [ticket/11580] Enable prefer-source option (should error way less)
  [ticket/11580] Enable --no-interaction option on composer for travis

Conflicts:
	.travis.yml