extend the Travis CI Build Matrix

.travis.yml

@@ -13,18 +13,56 @@
 
 language: c
 sudo: required
+
+os: linux
 dist: trusty
+
 services:
   - docker
 compiler:
   - gcc
-os:
-  - linux
-  - osx
 
 
+# test multiple distros, CPU Architectures and OS's
+jobs:
+  include:
+    # trusty
+    - os: linux
+      dist: trusty
+      arch: amd64
+
+    # xenial
+    - os: linux
+      dist: xenial
+      arch: amd64
+
+    - os: linux
+      dist: xenial
+      arch: arm64
+
+    # bionic
+    - os: linux
+      dist: bionic
+      arch: amd64
+
+    - os: linux
+      dist: bionic
+      arch: arm64
+
+    # focal
+    - os: linux
+      dist: focal
+      arch: amd64
+
+    - os: linux
+      dist: focal
+      arch: arm64
+
+    # macOS
+    - os: osx
+
 before_install:
   - ./.travis/install.sh
 
 script:
-  - ./.travis/run_tests.sh
+  - ./.travis/run_tests.sh