modify import in model/__init__.py to be compatible with python2

Author: Dan Jia

dr_spaam/bin/train.py

@@ -4,7 +4,7 @@
 
 from dr_spaam.dataset import get_dataloader
 from dr_spaam.pipeline.pipeline import Pipeline
-from dr_spaam.model import get_model
+from dr_spaam.model.get_model import get_model
 
 
 def run_training(model, pipeline, cfg):

dr_spaam/dr_spaam/model/__init__.py

@@ -1,5 +1,6 @@
+# Only import python2 compatible modules here
 from .dr_spaam import *
-# from .dr_spaam_fn import *
 from .drow_net import *
-from .losses import *
-from .get_model import *
+# from .dr_spaam_fn import *
+# from .losses import *
+# from .get_model import *