Bug#910613: Unecessary dependency on python3-tk

[Yuri D'Elia]

Package: python3-seaborn
Version: 0.8.0-1
Severity: normal

NMU version 0.8.0-1.1 add a Depends: python3-tk, however this dependency
shouldn't be there.

I fought hard to remove it in the first place.

If you follow the bug report in #896401 and #896003, the dependency is
triggered when using matplotlib.

matplotlib *already* recommends python3-tk.
That's already correct and enough.

matplotlib doesn't *depend* on it because the tk backend is *not*
required for matplotlib to work. matplotlib can work with agg, Qt or
cairo.

The python3-tk dependency is pulling extra useless dependencies on
headless systems.

Please remove the extra dependency.
Thanks

-- System Information:
Debian Release: buster/sid
  APT prefers unstable
  APT policy: (900, 'unstable'), (800, 'experimental'), (500, 'unstable-debug')
Architecture: amd64 (x86_64)

Kernel: Linux 4.18.0-2-amd64 (SMP w/8 CPU cores)
Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8), LANGUAGE=en_US.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)

Versions of packages python3-seaborn depends on:
ii  python3             3.6.6-1
ii  python3-matplotlib  2.2.2-4+b1
ii  python3-numpy       1:1.14.5-1+b1
ii  python3-pandas      0.23.3-1
ii  python3-scipy       1.1.0-1+b1

Versions of packages python3-seaborn recommends:
pn  python3-bs4    <none>
ii  python3-patsy  0.4.1+git34-ga5b54c2-1

python3-seaborn suggests no packages.