Print echo lines of the git commit sha and tag for use in echo_versio…

…ner_env_vars of other repos

build_test.sh

@@ -1,4 +1,10 @@
 #!/usr/bin/env bash
 set -Eeu
 
-make image
+repo_root() { git rev-parse --show-toplevel; }
+source "$(repo_root)/sh/lib.sh"
+
+make image
+echo
+echo "echo CYBER_DOJO_LANGUAGES_START_POINTS_SHA="$(git_commit_sha)""
+echo "echo CYBER_DOJO_LANGUAGES_START_POINTS_TAG="$(git_commit_tag)""