Fix 404 link to d1_instance_generator folder in documentation
In the MN API documentation for MNStorage.create (https://jenkins-ucsb-1.dataone.org/job/API%20Documentation%20-%20trunk/ws/api-documentation/build/html//apis/MN_APIs.html#MNStorage.create), I found a the following paragraph contains a broken link to d1_instance_generator:
"The system metadata included with the create call must contain values for the elements required to be set by clients (see System Metadata). The system metadata document can be crafted by hand or preferably with a tool such as generate_sysmeta.py which is available in the d1_instance_generator Python package. See documentation included with that package for more information on its operation."
The link to d1_instance_generator was to the SVN folder https://repository.dataone.org/software/cicore/trunk/d1_instance_generator which is currently a 404. I think the folder moved to /d1_test_utilities_python/src/d1_test/instance_generator.