Merge pull request #11 from edzer/stars

first shot at stars support in aoa; some tidying

DESCRIPTION

@@ -10,14 +10,14 @@ Authors@R: c(person("Hanna", "Meyer", email = "hanna.meyer@uni-muenster.de", rol
 Author: Hanna Meyer [cre, aut], Chris Reudenbach [ctb], Marvin Ludwig [ctb], Thomas Nauss [ctb], Edzer Pebesma [ctb]             
 Maintainer: Hanna Meyer <hanna.meyer@uni-muenster.de>
 Description: Supporting functionality to run 'caret' with spatial or spatial-temporal data. 'caret' is a frequently used package for model training and prediction using machine learning. This package includes functions to improve spatial-temporal modelling tasks using 'caret'. It prepares data for Leave-Location-Out and Leave-Time-Out cross-validation which are target-oriented validation strategies for spatial-temporal models. To decrease overfitting and improve model performances, the package implements a forward feature selection that selects suitable predictor variables in view to their contribution to the target-oriented performance.
-License: GPL (>= 3) | file LICENSE
+License: GPL (>= 2)
 URL: https://github.com/HannaMeyer/CAST
 Encoding: UTF-8
 LazyData: true
 Depends: R (>= 3.1.0)
 Imports: caret, stats, utils, ggplot2, graphics, reshape, FNN, plyr
 Suggests: doParallel, GSIF, randomForest, lubridate, raster, sp, knitr, mapview,
     rmarkdown, sf, scales, parallel, latticeExtra, virtualspecies, gridExtra, 
-    viridis, rgeos
+    viridis, rgeos, stars
 RoxygenNote: 7.1.0
 VignetteBuilder: knitr