update travis.yml

language: cpp

compiler: gcc

dist: xenial

dist: bionic

before_install:

  - sudo add-apt-repository -y ppa:ubuntu-toolchain-r/test

  - sudo bash -c "echo ttf-mssourcefonts-installer msttsourcefonts/accepted-mssourcefonts-eula select true | debconf-set-selections"

  - sudo apt-get update -qq

  - sudo apt-get install -y gcc-8 g++-8 cmake libcairo2-dev libharfbuzz-dev libfreetype6-dev msttsourcefonts ttf-mssourcefonts-installer

  - sudo update-alternatives --install /usr/bin/g++ g++ /usr/bin/g++-8 90

  - sudo fc-cache

  - sudo apt-get install -y gcc-8 g++-8 cmake libfreetype6-dev libharfbuzz-dev libfribidi-dev libcairo2-dev libfmt-dev

script:

  - fc-match "Arial,Helvetica,Helvetica Neue:style=Regular,Roman"

  - cmake .

  - make all test CTEST_OUTPUT_ON_FAILURE=1

  - make all