Handle changed nested objects

[ojongerius]

(Fallout from volCommunity/vol-django#86 )
If dependent resources change, we need either:

• Update before we create the container resource
• Parse the failed container resource creation, update the dependant resource and try again
• Do nothing

Example of a failure:

going to create item: {'title': 'Club Secretary - Special olympics South Canterbury | SEEK Volunteer', 'url': 'https://seekvolunteer.co.nz/volunteering/54479/club-secretary-special-olympics-south-canterbury', 'text': 'Special Olympics South Canterbury offers year-round sports training and competition for children and adults with an intellectual disability.  \nThey are in need of a club secretary who will manage all athlete and volunteer registrations, communicate with Special Olympics New Zealand and organise any required Club meetings throughout the year. \nSkill Set:\n\nStrength in relationship management;\n\nEffective communicator –verbally and in writing;\n\nComputer literacy including a good working knowledge of all Microsoft Office products;\n\nWell organised and able to delegate tasks;\n\nApproachable and a good listener;\n\nAn ability to maintain confidentiality when required.\nA more detailed job description can be provided on request.\nIf you would like the opportunity to make a difference and have time to assist our club please contact us!  \n\nYou are required to register as a volunteer with Special Olympics – a form will be provided on employment.\r\n', 'labels': [{'name': ' Disability Services'}], 'city': ' Canterbury', 'sites': [{'name': 'SEEK Volunteer', 'url': 'https://seekvolunteer.co.nz/'}], 'region': 'placeholder', 'country': 'NZ', 'organisation': {'name': 'Special Olympics New Zealand | SEEK Volunteer', 'url': 'https://seekvolunteer.co.nz/volunteering-organisations/325/special-olympics-new-zealand', 'description': 'Special Olympics New Zealand offers a year-round programme of sports training and competition for children and adults with intellectual disabilities.', 'city': ' National', 'region': 'placeholder', 'country': 'NZ'}, 'organisation_url': '/volunteering-organisations/325/special-olympics-new-zealand', 'site_name': 'SEEK Volunteer', 'site_url': 'https://seekvolunteer.co.nz/'}
2017-11-08 14:08:31 [urllib3.connectionpool] DEBUG: Starting new HTTP connection (1): localhost
2017-11-08 14:08:31 [urllib3.connectionpool] DEBUG: http://localhost:8000 "POST /api/jobs HTTP/1.1" 400 277