Add admin and orgs

Add recipes for creating admin users and creating organizations.

Borrowed functionality from @misheska at https://github.com/misheska-cookbooks/chef-server12

Would like to combine the functionality provided by these two cookbooks into one chef-server cookbook to rule them all. 
If this is to shortcut the typing later, I think we should do either:

1. Create `admin` as a hash and use that.
2. Just use the node attributes in the command.