modkit dmr output

[aganezov]

When running modkit dmr pair allow for output file to be in not-yet-existing directory.
Example (assumint output does not exist)

modkit dmr pair -a normal.bed.gz -b target.bed.gz --regions-bed regions.bed -o output/output.bed

currently dies with > Error! No such file or directory (os error 2)
Proposed behavior -- create output directory and write program output into output/output.bed

[ArtRand]

Fixed in https://github.com/nanoporetech/modkit/releases/tag/v0.2.1.