Add top-level progress bar

[thomasckng]

Is your feature request related to a problem? Please describe.
Currently, there is only progress bar within each strategy. Having a top-level progress bar that shows the number training or production loops would be nice.

Describe the solution you'd like
Add a progress bar that shows the progress of training and production loops

[Qazalbash]

I will second that because without progress bar it is hard to know to which extend the process will run.

[Qazalbash]

Hi @thomasckng, I have addressed this issue in #237, please take a look.