Be sure the node name and group name are unique.

I don't think we need multible groups and nodes with the same name. If you've already some version running it maybe requires a migration of the database by running the following commands:

	manage.py makemigrations
	manage.py migrate
Add readme file with link to the migrate script
Merge pull request #3 from drscream/master

Be sure the node name and group name are unique.