Use current HHVM

This provides the current HHVM version (3.17.1 as of this PR) and will track with each release (i.e. will be 3.18 when 3.18 is released).

If testing against HHVM LST versions is desired follow this guide. https://docs.travis-ci.com/user/languages/php#HHVM-versions

Should be able to change to container based Trusty after Q1-17 https://blog.travis-ci.com/2016-11-08-trusty-container-public-beta/

Author: photodude

.travis.yml

@@ -6,14 +6,7 @@ cache:
   directories:
     - $HOME/.composer/cache/files
 
-## PHP versions we test against
-php:
-  - 7.0
-  - 7.1
-  - nightly
-  - hhvm
-
-## Build matrix for lowest and highest possible targets
+## Build matrix for PHP versions we test against with lowest and highest possible targets
 matrix:
   include:
     - php: 7.0
@@ -23,6 +16,9 @@ matrix:
     - php: nightly
       env: dependencies=lowest
     - php: hhvm
+      sudo: true
+      dist: trusty
+      group: edge # until the next major travis stable update
       env: dependencies=lowest
     - php: 7.0
       env: dependencies=highest
@@ -31,6 +27,9 @@ matrix:
     - php: nightly
       env: dependencies=highest
     - php: hhvm
+      sudo: true
+      dist: trusty
+      group: edge # until the next major travis stable update
       env: dependencies=highest
   allow_failures:
     - php: hhvm