Travis: upgrade to Qt5 and Ubuntu 18.04 Bionic

Author: jnumm

.travis.yml

@@ -1,12 +1,12 @@
 language: cpp
 sudo: required
-dist: trusty
+dist: bionic
 compiler:
   - gcc
   - clang
 before_install:
   - sudo apt-get update -qq
-  - sudo apt-get install -qq libqt4-dev libqt4-opengl-dev libqglviewer-dev  
+  - sudo apt-get install -qq libqglviewer-dev-qt5
 before_script:
 script: ./scripts/travis_build_jobs.sh $VARIANT
 env: