build: Update HHVM for Travis to 3.12

Travis defaults 'hhvm' to 3.6.6 for back-compat, however newer
versions are available. The latest supported version on Travis is 3.12,
per <https://docs.travis-ci.com/user/languages/php#HHVM-versions>.
This also matches the version currently used in wmf production.

Bug: T75175
Change-Id: I1c562f61acf83aa7f558b2e11a6af81d13523dea

diff --git a/.travis.yml b/.travis.yml
index 9738605..80769dc 100644 (file)
--- a/.travis.yml
+++ b/.travis.yml
@@ -16,7 +16,7 @@ matrix:
     - env: dbtype=postgres
       php: 5.5
     - env: dbtype=mysql
-      php: hhvm
+      php: hhvm-3.12
     - env: dbtype=mysql
       php: 7