gpyopt is missing as a dependency

[stanleybak]

when using "bopt" I get an error. Maybe we could add it to the requirements so it auto installs?

[EthanJamesLew]

I added bopt as an PEP 508 extra_requires because it's a heavy requirement and not compatible with the latest versions of python. However, this adds a lot of confusion. I will add it to the default.