When running `growforest` with option `-adaboost` I get: ``` panic: interface conversion: *CloudForest.AdaBoostTarget is not CloudForest.BoostingTarget: missing method Boost goroutine 1 [running]: main.main.func1() [...]/github.com/ryanbressler/CloudForest/growforest/growforest.go:683 +0x1763 main.main() [...]/github.com/ryanbressler/CloudForest/growforest/growforest.go:748 +0x2673 ```