Cache embedmongo on CI

ci/scripts/common.sh

 source /opt/concourse-java.sh
 
 setup_symlinks
+if [[ -d $PWD/embedmongo && ! -d $HOME/.embedmongo ]]; then
+	ln -s "$PWD/embedmongo" "$HOME/.embedmongo"
+fi
+
 cleanup_maven_repo "org.springframework.boot"

ci/tasks/build-project.yml

@@ -7,6 +7,7 @@ outputs:
 caches:
 - path: maven
 - path: gradle
+- path: embedmongo
 run:
   path: bash
   args: