chore(deps): update docker.io/ubuntu docker tag to v18.10

This MR contains the following updates:

Package	Type	Update	Change
docker.io/ubuntu	final	minor	18.04 -> 18.10

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Dockerfile

-FROM docker.io/ubuntu:18.04
+FROM docker.io/ubuntu:18.10
 
 RUN apt-get update && \
     apt-get upgrade -y && \