travis: Use bionic instead of trusty.

No more need to compile libftdi1.

.travis.yml

@@ -1,42 +1,11 @@
-dist: trusty
+dist: bionic
 sudo: required
 
 before_install:
   - sudo add-apt-repository -y ppa:team-gcc-arm-embedded/ppa
   - sudo apt-get update -qq
   - pip install --user intelhex
-  - gpg --recv-keys 3CEA9B8868BC3852618EB5B4707F91A424F006F5
-  - wget http://www.intra2net.com/en/developer/libftdi/download/libftdi1-1.2.tar.bz2
-  - wget http://www.intra2net.com/en/developer/libftdi/download/libftdi1-1.2.tar.bz2.sig
-  - gpg --trust-model always --verify libftdi1-1.2.tar.bz2.sig
-  - tar -xjf libftdi1-1.2.tar.bz2
-  - sudo apt-get install -y build-essential libboost-all-dev gcc-arm-embedded libusb-1.0-0-dev libhidapi-dev
-
-install:
-  - cd libftdi1-1.2
-  - if [ "$TRAVIS_OS_NAME" = "linux" ];
-    then
-      sudo apt-get update -qq;
-      if [ "$ARCH" = "x86_64" ];
-      then
-        sudo apt-get install -qq libusb-1.0-0-dev;
-      elif [ "$ARCH" = "i386" ];
-      then
-        sudo apt-get install -qq gcc-multilib libusb-1.0-0-dev:i386 pkg-config:i386;
-        export CFLAGS="-m32";
-      fi
-    fi
-  - if [ "$TRAVIS_OS_NAME" = "osx" ];
-    then
-      brew update;
-      brew install libusb;
-    fi
-  - mkdir build
-  - cd build
-  - cmake ../
-  - make
-  - sudo make install
-  - cd ../../
+  - sudo apt-get install -y build-essential libboost-all-dev gcc-arm-embedded libusb-1.0-0-dev libhidapi-dev libftdi1 libftdi1-dev
 
 script:
   - make -C libopencm3 lib