Add script to identify if newer images are available in iron bank

Summary

Helper script to identify if any deployed packages/images have updates available in iron bank.

Relevant logs/screenshots

❯ ./scripts/latest.sh        
Update for registry1.dso.mil/ironbank/anchore/enterpriseui/enterpriseui:  3.0.1 ---->  3.0.2
Update for registry1.dso.mil/ironbank/elastic/eck-operator/eck-operator:  1.4.0 ---->  1.5.0
Update for registry1.dso.mil/ironbank/gitlab/gitlab/alpine-certificates:  13.8.0 ---->  13.9.0
Update for registry1.dso.mil/ironbank/gitlab/gitlab/gitaly:  13.8.0 ---->  13.9.0
Update for registry1.dso.mil/ironbank/gitlab/gitlab/gitlab-container-registry:  13.8.0 ---->  13.9.3
Update for registry1.dso.mil/ironbank/gitlab/gitlab/gitlab-exporter:  13.8.0 ---->  13.9.3
Update for registry1.dso.mil/ironbank/gitlab/gitlab/gitlab-shell:  13.8.0 ---->  13.9.0
Update for registry1.dso.mil/ironbank/gitlab/gitlab/gitlab-sidekiq:  13.8.0 ---->  13.9.0
Update for registry1.dso.mil/ironbank/gitlab/gitlab/gitlab-task-runner:  13.8.0 ---->  13.9.0
Update for registry1.dso.mil/ironbank/gitlab/gitlab/gitlab-webservice:  13.8.0 ---->  13.9.0
Update for registry1.dso.mil/ironbank/gitlab/gitlab/gitlab-workhorse:  13.8.0 ---->  13.9.3
Update for registry1.dso.mil/ironbank/opensource/coreos/kube-state-metrics:  v1.9.7 ---->  v1.9.8
Update for registry1.dso.mil/ironbank/opensource/grafana/grafana:  7.1.3-1 ---->  7.5.4
Update for registry1.dso.mil/ironbank/opensource/istio-1.8/operator:  1.8.4 ---->  1.8.5
Update for registry1.dso.mil/ironbank/opensource/istio-1.8/pilot:  1.8.4 ---->  1.8.5
Update for registry1.dso.mil/ironbank/opensource/istio-1.8/proxyv2:  1.8.4 ---->  1.8.5
Update for registry1.dso.mil/ironbank/opensource/jaegertracing/jaeger-operator:  1.22.0 ---->  1.22.1
Update for registry1.dso.mil/ironbank/opensource/kiali/kiali-operator:  v1.32.0 ---->  v1.33.1
Update for registry1.dso.mil/ironbank/opensource/kiali/kiali:  v1.32.0 ---->  v1.33.0
Update for registry1.dso.mil/ironbank/opensource/minio/mc:  RELEASE.2021-02-07T02-02-05Z ---->  RELEASE.2021-04-22T17-40-00Z
Update for registry1.dso.mil/ironbank/opensource/minio/minio:  RELEASE.2020-11-19T23-48-16Z ---->  RELEASE.2021-04-18T19-26-29Z
Update for registry1.dso.mil/ironbank/opensource/openpolicyagent/gatekeeper:  v3.3.0 ---->  v3.4.0
Update for registry1.dso.mil/ironbank/opensource/postgres/postgresql96:  9.6.18 ---->  9.6.20
Update for registry1.dso.mil/ironbank/opensource/prometheus/node-exporter:  v1.0.1 ---->  v1.1.2
Update for registry1.dso.mil/ironbank/opensource/prometheus/prometheus:  v2.22.0 ---->  v2.26.0
Update for registry1.dso.mil/ironbank/redhat/ubi/ubi8:  8.2 ---->  8.3