valr 0.8.3

• read_bigwig() now uses cpp11bigwig on CRAN. The set_strand param was removed to be
  more consistent with expected bigWig contents.

• read_gtf() was deprecated. The rtracklayer package used
  for this functionality is no longer a dependency of valr due to errors from
  CRAN AddressSantizer checks of the UCSC c-library code vendored in rtracklayer.

• valr now depends on R >= 4.0.0.