Replace getargspec with getfullargspec (pytorch#15396)

Summary:
Replace `getargspec` with `getfullargspec` to resolve test warnings. Fixes pytorch#15344 .
Pull Request resolved: pytorch#15396

Differential Revision: D13529548

Pulled By: zou3519

fbshipit-source-id: 50d3be92423a9ce89bc4895b67569663e1abbaa6

Author: epicfaace

test/common_utils.py

@@ -178,7 +178,10 @@ def to_gpu(obj, type_map={}):
 
 
 def get_function_arglist(func):
-    return inspect.getargspec(func).args
+    if sys.version_info > (3,):
+        return inspect.getfullargspec(func).args
+    else:
+        return inspect.getargspec(func).args
 
 
 def set_rng_seed(seed):