Update openshift.sh

Added configure_nodeRegisterScript method.  This method will generate a script on the 'broker' instance called 'register_nodes.sh' under root.  The script is designed to be used after you have finished creating your node instances.  It will parse the Apache Web Server (access) log for captured node details and register those nodes with the DNS.  The script will also add the discovered nodes to a district if you specified the district_name and district_size parameters.  Where district_name is the name of the district and district_size is either "small", "medium" or "large".