CI: Use bionic as base distro

Signed-off-by: falkTX <falktx@falktx.com>

.travis.yml

@@ -1,8 +1,5 @@
-os:
-  - linux
-
-sudo: required
-dist: trusty
+os: linux
+dist: bionic
 
 languages: c++
 compiler: gcc

.travis/before_install.sh

@@ -2,9 +2,10 @@
 
 set -e
 
-sudo add-apt-repository ppa:kxstudio-debian/kxstudio -y
-sudo add-apt-repository ppa:kxstudio-debian/mingw -y
-sudo add-apt-repository ppa:kxstudio-debian/toolchain -y
+sudo add-apt-repository -y ppa:kxstudio-debian/kxstudio
+sudo add-apt-repository -y ppa:kxstudio-debian/mingw
+sudo add-apt-repository -y ppa:kxstudio-debian/toolchain
+
 sudo apt-get update -qq
 sudo apt-get install kxstudio-repos
 sudo apt-get update -qq