Removes DeepSpeedDataSource (#100)

* Removes DeepSpeedDataSource

* dropping unused imports
Co-authored-by: Jeff Rasley <jerasley@microsoft.com>

deepspeed/pt/deepspeed_dataloader.py

@@ -3,26 +3,8 @@ Copyright 2019 The Microsoft DeepSpeed Team
 '''
 
 import torch
-import logging
 from torch.utils.data import DataLoader, RandomSampler
 from torch.utils.data.distributed import DistributedSampler
-from tqdm import tqdm
-
-
-class DeepSpeedDataSource(object):
-    def __init__(self, filenames):
-        all_lines = []
-        for filename in filenames:
-            logging.info("Start reading file %s" % filename)
-            with open(filename, "r") as f:
-                for i, line in enumerate(tqdm(f)):
-                    all_lines.append(line.strip())
-
-        self.all_lines = all_lines
-        self.len = len(self.all_lines)
-
-    def __len__(self):
-        return self.len
 
 
 class DeepSpeedDataLoader(object):