add Procfile to go_calls_ruby app
add Procfile to go_calls_ruby app

so that it will have a web process and be visible in v2 if staged as
Ruby app.

[finish #150502303]

Signed-off-by: Maria Shaldibina <dc03896a0185453e5852a5e0f0fab6cbd2e026ff@pivotal.io>

cloudfoundry/cli,cloudfoundry/cli,cloudfoundry/cli