Checking the draft changes of data structure using NDA API

[smpadhy]

Even though every time we pull the data dictionary from NDA using NDA REST API before editing or resuse, as per David's feedback, there is a chance that by the time the pull request is submitted and accepted, there might be draft changes to the form. We should check the hash of the form before creating a pull request to make sure we are making changes to the origin form. Again this is related to the issue #75