v0.10.0

v0.10.0 introduces the link-based UE that adopts the Frank-Wolfe algorithm with line search. It also includes several other major updates below.

1. Introduce generic downloading functions to replace download_sample_data_sets().
2. Introduce DTALiteClassic() and DTALiteMultimodal() to replace perform_network_assignment_DTALite() and run_DTALite(), respectively.
3. Add multiprocessing exception handling to DTALiteClassic().
4. Fix segmentation fault on DTALiteMultimodal() with Python 3.8 on Linux.
5. Optimize IO by precluding path geometry as default when outputting route_assignment.csv.