Use Ubuntu 18.04 as the base Linux version.

Author: freakboy3742

Dockerfile

@@ -1,7 +1,7 @@
-# Use Ubuntu 16.04 (xenial) as a base image. This ensures that we're using an
+# Use Ubuntu 18.04 (bionic) as a base image. This ensures that we're using an
 # old version of libc, maximizing the compatibility of the image when it is
 # included in an AppImage.
-FROM ubuntu:16.04
+FROM ubuntu:18.04
 
 # Install the build requirements for Python.
 RUN apt-get update -y && \