Change logs for gsl source package in Bionic

gsl (2.4+dfsg-6) unstable; urgency=medium

  * debian/control: Version is as 'Replaces: libgsl23 (<< 2.4+dfsg-4)'

 -- Dirk Eddelbuettel <email address hidden>  Wed, 09 Aug 2017 10:07:24 -0500