valr 0.6.0

Major changes

• trbl_interval() and trbl_genome() custom tibble subclasses have been deemed unnecessary and have been removed from the package.

• coercing GRanges to a valr compatible data.frame now uses the gr_to_bed() function rather than as.trbl_interal() methods.

Minor changes

• dplyr version < 0.8.0 is no longer supported due to unnecessary code bloat and challenges with handling multiple grouping structures (#359).

• The sort_by argument of bed_random() has been changed to sorted, and will now by default
  use bed_sort() to sort the output, rather than rely on naming the sorting columns. Sorting can
  be suppressed by using sorted = FALSE.

• bed_sort() now uses base R sorting with the radix method for increased speed. (#353)

• tbls processed by bed_merge()or bed_sort() no longer store either merged or sorted as attributes, due to these attributes being rarely checked in the codebase and potential sources of unexpected behavior.

Bug fixes

• Fixed bed_closest() to prevent erroneous intervals being reported when adjacent closest intervals are present in the y table. (#348)

• Factor columns that are not used for grouping are returned as factors rather than inappropriately being coerced to integer vectors (#360)