fix test on pytorch 1.6.0

test/test_matmul.py

@@ -51,12 +51,12 @@ def test_spmm_half_precision():
     src_dense[:, 2:4] = 0  # Remove multiple columns.
     src = SparseTensor.from_dense(src_dense)
 
-    other = torch.randn((2, 8, 2), dtype=torch.half, device='cpu')
+    other = torch.randn((2, 8, 2), dtype=torch.float, device='cpu')
 
-    expected = src_dense @ other
-    out = src @ other
+    expected = (src_dense.to(torch.float) @ other).to(torch.half)
+    out = src @ other.to(torch.half)
 
-    assert torch.allclose(expected, out, atol=1e-6)
+    assert torch.allclose(expected, out, atol=1e-2)
 
 
 @pytest.mark.parametrize('dtype,device', product(grad_dtypes, devices))