minor #1625 Travis - switch to trusty (keradus)
minor #1625 Travis - switch to trusty (keradus)

This PR was merged into the 1.12 branch.

Discussion
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Travis - switch to trusty

Before:
> Elapsed time 8 min 6 sec
> Total time for 28 min 17 sec

After:
> Elapsed time 6 min 43 sec
> Total time for 25 min

-------------------------------------------

Before:
> HipHop VM 3.5.0 (rel)

After:
> HipHop VM 3.6.6 (rel)

Commits
-------

5a9a225 Travis - set dist to trusty

Soullivaneuh/PHP-CS-Fixer,SpacePossum/PHP-CS-Fixer,lucasmichot/PHP-CS-Fixer,keradus/PHP-CS-Fixer,Slamdunk/PHP-CS-Fixer,FriendsOfPHP/PHP-CS-Fixer,kubawerlos/PHP-CS-Fixer,FriendsOfPHP/PHP-CS-Fixer,Soullivaneuh/PHP-CS-Fixer,felixgomez/PHP-CS-Fixer,felixgomez/PHP-CS-Fixer,Slamdunk/PHP-CS-Fixer,SpacePossum/PHP-CS-Fixer,lucasmichot/PHP-CS-Fixer,gharlan/PHP-CS-Fixer,gharlan/PHP-CS-Fixer,GrahamCampbell/PHP-CS-Fixer,kubawerlos/PHP-CS-Fixer,keradus/PHP-CS-Fixer,GrahamCampbell/PHP-CS-Fixer