geotargets 0.1.0

• Created tar_terra_rast() and tar_terra_vect() for targets that create SpatRaster and SpatVector objects, respectively
• Created tar_terra_sprc() that creates a SpatRasterCollection object.
• geotargets_options_get() and geotargets_options_set() can be used to set and get options specific to geotargets.
• geotargets now requires targets version 1.7.0 or higher
• fixed a bug where resources supplied to tar_terra_*() were being ignored (#66)