Add a DNS router to add new VM entries to a central domain

[sunbiz]

Deploy a DNS router in a stable location that will listen to input from newly launched VMs, so that they can have their own domain names.

This is a sub-issue of #7 because a subdomain is required to get an SSL certificate. A skeletal startup script that pings the router is available here - https://github.com/iupui-soic/dynaswap/blob/master/shell-scripts/DAR.sh , but this issue is to track the code and updates to create the router itself. The DNS router should be a simple app that takes the IP and user launching the VM and post it to a DNS server.

the default implementation may use a externalized authentication to a REST service to a DNS server.

[sunbiz]

The DAR has been deployed to dynaswap.info. The following script needs to be run to be able to get a DNS A record created with the appropriate IP

curl -X POST "https://dynaswap.info/DAR" -d "{\"ip\": \"$(curl https://diagnostic.opendns.com/myip)\"}"