Switch to xenial [ci skip]

Author: probonopd

tests/tests-environment.sh

@@ -2,7 +2,7 @@
 
 set -e
 
-sudo add-apt-repository --yes ppa:beineri/opt-qt593-trusty
+sudo add-apt-repository --yes ppa:beineri/opt-qt593-xenial
 sudo apt-get update -qq
 
 wget https://ftp.fau.de/debian/pool/main/p/patchelf/patchelf_0.8-2_amd64.deb