This function is called during the second phase of SACOBRA cobraPhaseII to train the surrogate models for objective and constarint functions
of the optimization problem passed to the SACOBRA framework. This function takes all the so-far evalauted points stored in cobra$A and builds
trainSurrogates(cobra)an object of class COBRA, this is a (long) list containing all settings
from cobraPhaseII
cobra, an object of class COBRA,
with the following elements modified:
constraintSurrogatessurrogate models for all constraints
fitnessSurrogatesurrogate model for objective function
fitnessSurrogate1surrogate model for objective function, w/o plog
fitnessSurrogate2surrogate model for objective function, with plog