Changed all external links to https

[SwarajBaral]

Fixes #984

Description of the Change

Changed all external links from http:// to https://.

Checklist

• PR only contains one change (considered splitting up PR)
• unit-test added
• documentation updated
• CHANGELOG.md updated (only for user relevant changes)
• author name in AUTHORS

[codecov]

Codecov Report

Merging #989 (83d56da) into master (4f596d7) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master     #989   +/-   ##
=======================================
  Coverage   96.82%   96.82%           
=======================================
  Files          65       65           
  Lines        3906     3906           
=======================================
  Hits         3782     3782           
  Misses        124      124           

Impacted Files	Coverage Δ
rest_framework_json_api/django_filters/backends.py	100.00% <ø> (ø)
rest_framework_json_api/filters.py	100.00% <ø> (ø)

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[sliverc]

Thanks for working on this. See inline comments. Mainly though should the links localhost and 127.0.0.1 remain with http as those are internal and the runserver does not provide https.

[SwarajBaral]

@sliverc Fixed the remaining issues, kindly check.

[sliverc]

Thanks. LGTM.