.travis.yml: Add Ubuntu 20.04
It's been more than one year since Focal Fossa Ubuntu 20.04 was
released.  Add it as yet another CI machine to check our code base.
@@ -24,6 +24,16 @@ jobs:
- ./build/csp_arch
- ./build/csp_server_client -t
+ - name: Linux Ubuntu 20.04, GCC
+ os: linux
+ dist: focal
+ before_install:
+ - sudo apt-get -y install libzmq3-dev libsocketcan-dev libsocketcan2
+ script:
+ - python examples/buildall.py
+ - ./build/csp_arch
+ - ./build/csp_server_client -t
+
- name: Mac OS 10.13, XCode 9, GCC
os: osx
osx_image: xcode9.4.1
