Abstract away redundant code into set_dataset_key method
Abstract away redundant code into set_dataset_key method

* wqflask/base/data_set.py (Dataset):
- Add set_dataset_key
- Remove __call__ method

pjotrp/genenetwork2,zsloan/genenetwork2,genenetwork/genenetwork2,genenetwork/genenetwork2,zsloan/genenetwork2,genenetwork/genenetwork2,pjotrp/genenetwork2,pjotrp/genenetwork2,zsloan/genenetwork2,genenetwork/genenetwork2,zsloan/genenetwork2,pjotrp/genenetwork2,pjotrp/genenetwork2