Added plot for cov_change acc. ref.
Added plot for cov_change acc. ref.

Simple first derivative
mitenjain/nanopore,mitenjain/nanopore,mitenjain/nanopore,mitenjain/nanopore,mitenjain/nanopore,mitenjain/nanopore,mitenjain/nanopore,benedictpaten/marginAlign,benedictpaten/marginAlign,mitenjain/nanopore,isovic/marginAlign,benedictpaten/marginAlign,isovic/marginAlign