bugs when using pytorch1.1.0

[LifeIsSoSolong]

thanks for your contribution, Pytorch has updated to 1.3 now . So I try to run your code in pytorch1.1.0, but I went some bugs .
the main bug is in CenterNet/src/lib/models/networks/DCNv2/_ext/dcn_v2
/init.py:
error:ImportError: torch.utils.ffi is deprecated. Please use cpp extensions instead.

I tried to fix it according to "pytorch/pytorch#15645" but failed , So you have some advice or Do you have plan to rewritte it in pytorch>=1.0 ?