Update to trusty builds

.travis.yml

@@ -1,18 +1,24 @@
 language: php
 
 sudo: false
+dist: trusty
+
+php:
+  - 5.4
+  - 5.5
+  - 5.6
+  - 7.0
+  - 7.1
+  - hhvm
+  - nightly
 
 matrix:
   include:
-        - php: 5.3
+    - dist: precise
-        - php: 5.3
+      php: 5.3
+    - dist: precise
+      php: 5.3
       env: deps=low
-        - php: 5.4
-        - php: 5.5
-        - php: 5.6
-        - php: 7
-        - php: 7.1
-        - php: hhvm
   fast_finish: true
 
 before_script: