Remove old plugins from plugin registry - when adding new machineexec & theia, remove old versions too

2020-08-28 12:15:34,034 - atomic_reactor.plugins.imagebuilder - INFO - [ERROR] Could not read image metadata through skopeo inspect --tls-verify=false; skip registry.redhat.io/codeready-workspaces/plugin-java11-openj9-rhel8:2.2
2020-08-28 12:15:34,035 - atomic_reactor.plugins.imagebuilder - INFO - [ERROR] Remove v3/plugins/redhat/java11/0.50.0/meta.yaml from registry.
2020-08-28 12:15:34,038 - atomic_reactor.plugins.imagebuilder - INFO -   Reason:     Registry registry.redhat.io/codeready-workspaces/plugin-java11-openj9-rhel8:2.2:
2020-08-28 12:15:34,039 - atomic_reactor.plugins.imagebuilder - INFO -     time="2020-08-28T12:15:23Z" level=fatal msg="Error parsing image name \"docker://registry.redhat.io/codeready-workspaces/plugin-java11-openj9-rhel8:2.2\": error pinging docker registry registry.redhat.io: Get http://registry.redhat.io/v2/: dial tcp 104.113.9.148:80: connect: connection refused"
2020-08-28 12:15:34,039 - atomic_reactor.plugins.imagebuilder - INFO -     Registry registry-proxy.engineering.redhat.com/rh-osbs/codeready-workspaces-plugin-java11-openj9-rhel8:2.2:
2020-08-28 12:15:34,040 - atomic_reactor.plugins.imagebuilder - INFO -     time="2020-08-28T12:15:24Z" level=fatal msg="Error parsing image name \"docker://registry-proxy.engineering.redhat.com/rh-osbs/codeready-workspaces-plugin-java11-openj9-rhel8:2.2\": Error reading manifest 2.2 in registry-proxy.engineering.redhat.com/rh-osbs/codeready-workspaces-plugin-java11-openj9-rhel8: manifest unknown: manifest unknown"
2020-08-28 12:15:36,239 - atomic_reactor.plugins.imagebuilder - INFO - running 'if [[ ${USE_DIGESTS} == "true" ]]; then ./write_image_digests.sh v3; fi' failed with exit code 1

$ ./build/scripts/list_referenced_images.sh v3/ | grep -v :2.4 | grep plugin-java

registry.redhat.io/codeready-workspaces/plugin-java11-rhel8:2.2
registry.redhat.io/codeready-workspaces/plugin-java11-rhel8:2.3
registry.redhat.io/codeready-workspaces/plugin-java8-rhel8:2.2
registry.redhat.io/codeready-workspaces/plugin-java8-rhel8:2.3

./v3/plugins/redhat/dependency-analytics/0.0.13a/meta.yaml
./v3/plugins/redhat/vscode-yaml/0.4.0/meta.yaml

./v3/plugins/redhat/java11/0.50.0/meta.yaml 
./v3/plugins/redhat/java11/0.55.1/meta.yaml 
./v3/plugins/redhat/java11/0.57.0/meta.yaml 

./v3/plugins/redhat/java/0.62.0/meta.yaml
./v3/plugins/redhat/java8/0.62.0/meta.yaml

./v3/plugins/redhat/java11/0.62.0/meta.yaml 
./v3/plugins/redhat/quarkus-java11/1.3.0a/meta.yaml 
./v3/plugins/redhat/vscode-apache-camel/0.0.23/meta.yaml 
./v3/plugins/sonarsource/sonarlint-vscode/1.15.0/meta.yaml