chore: Add Ubuntu 20.04 image for Travis

.travis.yml

@@ -19,6 +19,10 @@ matrix:
       env:
         - VM=ubuntu
         - TAG=18.04
+    - os: linux
+      env:
+        - VM=ubuntu
+        - TAG=20.04
     - os: linux
       env: 
         - VM=mxe

docker/Dockerfile.ubuntu_20.04

@@ -0,0 +1,21 @@
+FROM ubuntu:20.04
+
+ENV DEBIAN_FRONTEND=noninteractive
+RUN apt-get update && apt-get install -y \
+    autoconf \
+    automake \
+    clang \
+    g++ \
+    libtool \
+    libsnmp-dev \
+    libxml2-dev \
+    libxslt1-dev \
+    make \
+    nsis \
+    cmake \
+    git \
+    qt5-default \
+    ccache
+
+WORKDIR /
+CMD ["bash"]

docker/travis.ubuntu_20.04.sh

@@ -0,0 +1,10 @@
+#!/bin/bash
+
+set -e -x
+
+mkdir -p /fwbuilder/build
+cd /fwbuilder/build
+cmake .. -DCMAKE_BUILD_TYPE=Debug
+make -j$(nproc)
+make install
+QT_QPA_PLATFORM=vnc ctest --verbose