update travis.yml

language: cpp

compiler: gcc

dist: bionic

sudo: required

os:

  - linux

  - osx

compiler:

  - gcc

  - clang

before_install:

  - sudo apt-get update -qq

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

  - if [[ "${TRAVIS_OS_NAME}" == "linux" ]]; then sudo apt-get update -qq; fi

  - if [[ "${TRAVIS_OS_NAME}" == "linux" ]]; then sudo apt-get install -y cmake libfreetype6-dev libharfbuzz-dev libfribidi-dev libcairo2-dev libfmt-dev; fi

  - if [[ "${TRAVIS_OS_NAME}" == "osx" ]]; then brew update; fi

  - if [[ "${TRAVIS_OS_NAME}" == "osx" ]]; then brew install freetype harfbuzz fribidi cairo cppformat; fi

script:

  - cmake .