missing "id" option in read_table

[janxkoci]

The read_table function lacks some options the other read_delim-based functions have, most importantly for me the id option. I have many whitespace-delimited files (the kind read_table is meant to handle) and I want to load them all with a map call followed with bind_rows, but the lack of id option makes it hard to keep track of which data comes from which input file.

Moreover, it makes the read_table function inconsistent with other read functions, for no obvious reason.