pool 1.0.2

• No longer depends on the withr package, by instead requiring R 3.6.

• Add wrappers for dbplyr generics db_col_types() (#171) and
  db_copy_to() (#172).

• Pool no longer generates spurious messages about needing to use
  in_schema() or avoiding the use of ident_q().

• Add support for new DBI generics that return Arrow objects.