TimeSeriseLayer will not remove properly if not on the first layer in the RasterDataCollection

[kotfic]

This has to do with how we store the key/value pair in M.layers._layers. the _remove_layer callback takes a name (the name of the layer currently on the map) and then tries to remove that layer on M.layers._layer. If that isn't the first layer it won't be found in M.layers._layers.