Update CNB tools

Author: cf-buildpacks-eng

scripts/install_shim_tools.sh

@@ -0,0 +1,23 @@
+#!/bin/bash
+set -euo pipefail
+
+cd "$( dirname "${BASH_SOURCE[0]}" )/.."
+source .envrc
+go mod download
+
+if [ ! -f .bin/ginkgo ]; then
+  go get -u github.com/onsi/ginkgo/ginkgo
+fi
+if [ ! -f .bin/buildpack-packager ]; then
+  go install github.com/cloudfoundry/libbuildpack/packager/buildpack-packager
+fi
+
+if [ ! -f .bin/cnb2cf ]; then
+    go install github.com/cloudfoundry/cnb2cf/cmd/cnb2cf
+    ./scripts/build.sh
+    if [ -f .bin/statik ]; then
+        rm .bin/statik
+    fi
+fi
+
+go mod tidy