Generate certificate for NginX

In order to allow Nginx to respond to HTTPS requests on port 443 we need to add a signed certificate to the server.

For OS X, in order to make things simple, we will use the pre-generated self-signed wildcard certificate for *.metadatacenter.orgx

On RHEL 6.6 there are more choices:

• one could generate the self-signed certificate for the server
• one could buy a certificate from a Certification Authority
• one could use the a free service, for instance "Let's Encrypt'

Currently we are using the "Let's Encrypt' service for our server, but we also include the documentation on how to create the self-signed certificate.