Batch the variant data into a single request

Fixes #28

Signed-off-by: Ryan O'Hara <oharar@email.chop.edu>
There is a lot of overhead happening here with initializing separate resources and deserializing data form the returned response. Change this to:

```python
resource = SampleResultResource()

for id in request.data['ids']:
    data.append(resource.get(request, id))
```