Update .gitlab-ci.yml, .metrics-dashboard.yml, Dockerfile

Dockerfile

+# This file is a template, and might need editing before it works on your project.
+# This Dockerfile installs a compiled binary into a bare system.
+# You must either commit your compiled binary into source control (not recommended)
+# or build the binary first as part of a CI/CD pipeline.
+
+FROM buildpack-deps:buster
+
+WORKDIR /usr/local/bin
+
+# Change `app` to whatever your binary is called
+Add app .
+CMD ["./app"]