Adding Cowboy to a supervision tree

[CrowdHailer]

The cowboy adapter currently cannot be started under a project applications supervision tree.

Cowboy, by design, starts a server under its application supervision tree when using :cowboy.start_http/4.

It is possible to start it under a project supervisor. and we would like to add that functionality to the cowboy adapter.

See:

• Best way to start a plug router under supervision
• plug adapter for child spec

[CharlesOkwuagwu]

Ok cool, so we switch to cowboy.child_spec. That would be better.

[CrowdHailer]

@CharlesOkwuagwu I have opened a PR #35 to tackle this. It's not using child_spec but I think an even better solution of just defining a start_link function. This is better because it allows you to start a application directly, useful for testing