Update tomcat Docker tag

This MR contains the following updates:

Package	Type	Update	Change
tomcat	ironbank-docker	patch	10.0.18-jdk8-openjdk -> 10.0.20-jdk8-openjdk
tomcat		minor	10.0.18 -> 10.1.0
tomcat	stage	patch	10.0.18-jdk8-openjdk -> 10.0.20-jdk8-openjdk

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