Fixed: Package Dependency Issues

[AlexChen539]

1. The file predict.py and package deep_sort_pytorch should be put under the root folder to omit import errors.
2. In deep_sort_pytorch/sort and deep_sort_pytorch/deep_sort, np.float should be changed to np.float32; np.int should be changed to np.int32. Numpy does not have float or int in the current version of package.

Hope this helps someone.