Configure HTTPS for Argo

[jpolchlo]

Previous iterations of the Argo application module relied on a self-signed certificate to have secure access over HTTPS. This is obviously only a temporary solution, which needs to be fixed by issuing a genuine certificate through an official authority. In this case, we want to use AWS ACM to issue the cert. This should then be applied to the Argo service load balancer to complete the setup. This PR makes the needed changes to get this all working.

[jpolchlo]

Current status: this is not completely working. I've been able to issue the certificate and get the load balancer configured to use it. However, Argo seems to be quite unhappy, and does not allow for the Argo server interface to communicate with the backend controller. The end result is that while it is possible to go to https://argo.compute.azavea.com, log in, and see the Argo server interface, that interface allows no actions. It complains with a Failed to load version/info Error: Unauthorized error message. Logs for both the Argo server and Argo controller show nothing specific to indicate what the error is. Browser console info shows that requests to

scheme:   https
host:     argo.compute.azavea.com
filename: /api/v1/userinfo

return with a 403. This is surely to do with the fact that these requests are being forwarded to https://argo.compute.azavea.com, and the token that is accompanying the request is not correct. There must be some configuration that I am not setting correctly, but the docs for Argo seem to be very poor for this.

I'm going to have to punt on this for the moment. I've spent far too much time here already.