Upgraded the CI script to use Ubuntu 16.04.

ddobrev · ddobrev · commit 2fe8d21f21a3 · 2018-10-14T01:43:35.000+03:00
Signed-off-by: Dimitar Dobrev &lt;dpldobrev@protonmail.com&gt;
diff --git a/.travis.yml b/.travis.yml
@@ -5,7 +5,7 @@ os:
   - linux
   - osx
 
-dist: trusty
+dist: xenial
 
 addons:
   apt:
