Add build index script

Add a script that can be used to quickly build index containing
test operator. The script pushes the index to quay.io by default.

Example of useage:

USER=quayio-nick TAG=xyz ./hack/build_index.sh

Author: lpiwowar

hack/build_index.sh

@@ -0,0 +1,28 @@
+#!/bin/bash
+#
+# This command builds test-operator index and pushes it to quay.io. Podman
+# should be authenticated against quay.io prior to the execution of this
+# command.
+#
+#   USER=quay-nickname TAG=xyz ./hack/build_index.sh
+#
+
+set -x
+
+USER=${USER:-$USERNAME}
+REGISTRY=${REGISTRY:-quay.io}
+IMAGE_NAME=${IMAGE_NAME:-test-operator}
+BUNDLE_IMAGE_NAME=${BUNDLE_IMAGE_NAME:-test-operator-bundle}
+INDEX_IMAGE_NAME=${INDEX_IMAGE_NAME:-test-operator-index}
+TAG=${TAG:-latest}
+
+make docker-build IMG=${REGISTRY}/${USER}/${IMAGE_NAME}:${TAG}
+make docker-push IMG=${REGISTRY}/${USER}/${IMAGE_NAME}:${TAG}
+
+make bundle IMG=${REGISTRY}/${USER}/${IMAGE_NAME}:${TAG}
+make bundle-build BUNDLE_IMG=${REGISTRY}/${USER}/${BUNDLE_IMAGE_NAME}:${TAG}
+make bundle-push BUNDLE_IMG=${REGISTRY}/${USER}/${BUNDLE_IMAGE_NAME}:${TAG}
+
+export BUNDLE_IMG=${REGISTRY}/${USER}/${BUNDLE_IMAGE_NAME}:${TAG}
+make catalog-build CATALOG_IMG=${REGISTRY}/${USER}/${INDEX_IMAGE_NAME}:${TAG}
+make catalog-push CATALOG_IMG=${REGISTRY}/${USER}/${INDEX_IMAGE_NAME}:${TAG}