Option to create a resource without overwriting existing records #37

The core API currently only supports apply methods, which, if there is an existing resource with the same id, will update the existing record. There is no distinction between the response after creating a new resource vs. updating one.

There should be a way to create a resource - this action should fail if there is an existing resource already registered in the system.

We can either alter the existing apply method to take in an argument or add separate create methods.