How to fix a Deprecation Warning in Django 1.9
You don't have to "fix" Deprecation Warnings as they are, well, only warnings and things still work. However, if you'll decide to update they might break your app. So usually it's a good idea to rewrite the parts with warnings to new interfaces, that are hinted in those warnings if it's in your code. If it's in some side library you use, then you might want to wait if the library creator will update his/her library in the next release.
Regarding your particular warnings, unless you'll decide to update to Django 1.10, your code should work well.
I am a new user of the Django Framework. I am currently building a REST API with the django_rest_framework. When starting my server I am getting deprecation warnings that I have no idea how to fix.

RemovedInDjango110Warning: 'get_all_related_objects is an unofficial API that has been deprecated. You may be able to replace it with 'get_fields()'
    for relation in opts.get_all_related_objects()

The above is the first of these. Does anyone know how to fix this issue. All I have in my API at the minute is standard rest calls using the built in ModelViewSet and I have also overwritten the default authentication & user system with my own so I have no idea why I'm getting these warnings as I have been using Django 1.9 from the start. 
I also got this:

RemovedInDjango110Warning: render() must be called with a dict, not a RequestContext

From my initial research this is related to templates. I am not using any templates so I don't know why this is coming up.
Can anyone help me to fix these issues?