Inclusion of other adquisition functions

[oarcelus]

I was wondering if it would be possible to includo other adquistion functions in the library.

• Predictive Entropy Search
• Portfolios of adquisition functions
  -...

[till-m]

Hey @oarcelus,

we're in the process of making acquisition functions easier to customize, see #447. The PR is currently on hold though, waiting for other changes. However the code is functional, so if you need this urgently, you should be able to install and create the functions you need based off of that branch. I hope this helps.