Added prediction function for validation set
Takes in pars from output/pred_pars.tab and
calculates the predicted probability of invasion for each site in the validation set.
Generalized predict_p() to handle m prediction vectors
prediction function now writes to file output/pred_p.tab
Bootstrap resampling in runtype 1 implimented.
Simplex is still slow to converge - might need tolerance loosening.
fixed prediction probs and tests with sims
quick script to check validation data using alt-met and AUC