Update CNS ubuntu version to 20.04 (#772)

csfmomo · web-flow · commit c1334728ce65 · 2021-01-28T12:19:31.000-08:00
diff --git a/cns/Dockerfile b/cns/Dockerfile
@@ -1,5 +1,5 @@
 # Use a minimal image as a parent image
-FROM ubuntu:19.10
+FROM ubuntu:20.04
 ARG CNS_BUILD_ARCHIVE
 
 # Install plugin
