config: added a puma config file
config: added a puma config file

This config file is meant to be used either for development purposes, or
production environments (e.g. inside of a Docker container).

Signed-off-by: Miquel Sabaté Solà <b4d70704b9e7df580cab34510621dbd0aacb2dfd@suse.com>

SUSE/Portus,krishnak9/Portus,angry-tony/Portus-20170827,mssola/Portus,mssola/Portus,krishnak9/Portus,mssola/Portus,angry-tony/Portus-20170827,angry-tony/Portus-20170827,angry-tony/Portus-20170827,SUSE/Portus,SUSE/Portus,SUSE/Portus,mssola/Portus,krishnak9/Portus,krishnak9/Portus