utils: spin out jsonref utils to inspire-utils

[jacquerie]

These two guys:

inspire-dojson/inspire_dojson/utils/__init__.py

Lines 77 to 85 in 404f7ee

	def get_recid_from_ref(ref_obj):
	"""Retrieve recid from jsonref reference object.
	If no recid can be parsed, returns None.
	"""
	if not isinstance(ref_obj, dict):
	return None
	url = ref_obj.get('$ref', '')
	return maybe_int(url.split('/')[-1])

and

inspire-dojson/inspire_dojson/utils/__init__.py

Lines 101 to 109 in 404f7ee

	def get_record_ref(recid, endpoint='record'):
	"""Create record jsonref reference object from recid.
	None recids will return a None object.
	Valid recids will return an object in the form of: {'$ref': url_for_record}
	"""
	if recid is None:
	return None
	return {'$ref': absolute_url('/api/{}/{}'.format(endpoint, recid))}

.

The problem is that they depend on absolute_url, so this requires #57 to be fixed.