run DROIDSLAM on cpu

[zhangjd1029]

Thank you very much for your admirable work.

I have run DROIDSLAM on a GPU and run a lot of datasets, as well as in real-time. Now I want to run a comparative experiment on a CPU. I browsed your code and saw many statements related to "device=" and "cuda". Do I need to modify all of these statements, or do I just need to modify a certain part? I have no experience in this area. Can you give me some suggestions？

Thank you very much. Looking forward to your reply