tidyr 1.1.3

• tidyr verbs no longer have "default" methods for lazyeval fallbacks. This
  means that you'll get clearer error messages (#1036).

• uncount() error for non-integer weights and gives a clearer error message
  for negative weights (@mgirlich, #1069).

• You can once again unnest dates (#1021, #1089).

• pivot_wider() works with data.table and empty key variables (@mgirlich, #1066).

• separate_rows() works for factor columns (@mgirlich, #1058).