Remove unnecessary constraints

See merge request !2

* Build-Depends: Drop versioned constraint on python3-astropy and python3-matplotlib.

Changes-By: deb-scrub-obsolete

Fix some issues reported by lintian

See merge request !1

Changes-By: lintian-brush
Fixes: lintian: out-of-date-standards-version
See-also: https://lintian.debian.org/tags/out-of-date-standards-version.html

Changes-By: lintian-brush
Fixes: lintian: upstream-metadata-file-is-missing
See-also: https://lintian.debian.org/tags/upstream-metadata-file-is-missing.html
Fixes: lintian: upstream-metadata-missing-bug-tracking
See-also: https://lintian.debian.org/tags/upstream-metadata-missing-bug-tracking.html
Fixes: lintian: upstream-metadata-missing-repository
See-also: https://lintian.debian.org/tags/upstream-metadata-missing-repository.html

Changes-By: lintian-brush
Fixes: lintian: package-uses-old-debhelper-compat-version
See-also: https://lintian.debian.org/tags/package-uses-old-debhelper-compat-version.html

Update to upstream version '0.3.0'
with Debian dir 184259a5eb762ef1659ca76050c63f4b3d5fc99e

Update to upstream version '0.2.1'
with Debian dir d7fe6620a91e97ccb3627a08be91802d367aa54c

Update to upstream version '0.1.0+dfsg'
with Debian dir ebbc41b377a1a64776829f02fa1b8d9e3d105ccd

Update to upstream version '0.1.0+dfsg'
with Debian dir e60862b53a5205699d381afca745e6053b5d1210