Updated the way var is read in from anndata2seurat to make it workable with old and new versions of seurat.

[jhaberbe]

I ran into a problem that occurs due to the naming scheme changes between older and newer versions of "var": meta.features / meta.data. I just added the following code to seurat2anndata

Someone else had this before (#82), and it seems like a quick fix that worked for me.

var <- .regularise_df(
  if (slotExists(Seurat::GetAssay(obj, assay), "meta.features")) {
    Seurat::GetAssay(obj, assay)@meta.features
  } else if (slotExists(Seurat::GetAssay(obj, assay), "meta.data")) {
    Seurat::GetAssay(obj, assay)@meta.data
  } else {
    stop("No meta.features or meta.data found on assay.")
  },
  drop_single_values = drop_single_values
)
rownames(var) <- rownames(Seurat::GetAssay(obj, assay = assay)@features@.Data)