Test predictive entropy search

[maxentile]

@karalets suggested to compare the performance of the acquisition functions built into GPyOpt with the PES acquisition function described in this paper: http://papers.nips.cc/paper/5324-predictive-entropy-search-for-efficient-global-optimization-of-black-box-functions.pdf

A MATLAB/C implementation is available here: https://bitbucket.org/jmh233/codepesnips2014

We can test this in probably the fewest lines of code by calling the Python model from within MATLAB (replacing line 19 in runPES.m).