Skopt Progress bar

[antoniocmf]

I've started recently running some optimizations using the skopt method and I thought It would be really interesting to add something like a tqdm progress bar to the optimization process.

Unfortunately as I'm new to Python, I wouldn't know how to help implementing this.

Just something I thought would be nice to share.

Thanks!

[kernc]

tqdm is already used for non-skopt optimization. I guess we forgout about it when skopt was introduced.

Please raise this enhancement request on the issue tracker.

[kernc]

Filed as #280.