snap to nucleotide boundaries when resizing exon

fixes #44

Signed-off-by: Harsh Gupta <gupta.harsh96@gmail.com>
When snapping exon to nucleotide boundaries, ensure vertical line follows.

Signed-off-by: Anurag Priyam <anurag08priyam@gmail.com>
Merge branch 'snap'

* snap:
  snap to nucleotide boundaries when resizing exon
  When snapping exon to nucleotide boundaries, ensure vertical line follows.

close #44

Signed-off-by: Anurag Priyam <anurag08priyam@gmail.com>