Add progress bar

[ayan-b]

We can add a progress bar, internet speed to gdc.download(...) and other similar functions. Would like to work on this if I get a green signal. :)

[ayan-b]

I have worked something similar to this here.

[yunhailuo]

Sure. That sounds fine. Two minor points:

• Nice to have but we don't need to overkill this. This is not the core feature and should not have too much impact on performance.
• Maybe make it stderr or something like that so it won't get into log or stdout if people want to collect logs whatever way.

[RJ722]

Hi, I was just reading through the comments and thought that I could chime in. I read a pretty good discussion on Unix StackExchange regarding stream placement for progress bars and hope that it might help here.

[ayan-b]

@RJ722 Thanks! I will keep in mind while implementing,