Close #2308.

To run e2e tests after Apollo server is up, we use start-server-and-test that internally use wait-on.

For http(s) resources wait-on will check that the requests are returning 2XX (success) to HEAD or GET requests (after following any redirects).

~ wait-on documentation

• http://localhost:4040 returns a 404, so it won't works
• http://localhost:4040/graphql returns a 405 because wait-on use a HEAD request
• http-get://localhost:4040/graphql for forcing a GET request, but it returns a 400 because I didn't provided any query parameter.
• http-get://localhost:4040/graphql?query={cwd} works fine