Switch to LTS version of Ubuntu

'dazzle build' fails using 20.10 as the base on 'apt-get update'

Author: kylos101

example/base/Dockerfile

@@ -1,4 +1,4 @@
-FROM ubuntu:20.10
+FROM ubuntu:20.04
 
 COPY readme.md /
 RUN  apt-get update && apt-get install -y curl tar bash && rm -rf /var/lib/apt/lists/*