Lock Travis distro so new future defaults will not break the build

clue · clue · commit c8d8b36273df · 2017-08-28T12:22:35.000+02:00
diff --git a/.travis.yml b/.travis.yml
@@ -7,6 +7,9 @@ php:
   - 5.6
   - 7
 
+# lock distro so new future defaults will not break the build
+dist: precise
+
 # also test against HHVM, but require "trusty" and ignore errors
 matrix:
   include:
