Alter puppet class to use usual nginx config for staging machines

There were two nginx configuration files, one for prod and pprd and
a second for staging. This done to open port 8088 to solr only on
staging machines. This change moves the solr port info into its own
configuration file, and then only installs that file on staging
machines. End result is the same thing. But now the main config is not
duplicated.
Merge pull request #124 from ndlib/alter-nginx-puppet

Alter puppet class to use usual nginx config for staging machines