properly anchor ends of url patterns

[n2ygk]

Description of the Change

The example usage of url() in example/urls.py and example/urls_test.py was missing
the $ anchor at the end of most patterns. Best practice is to fully specify an anchored URL to avoid inadvertently matching a substring.

For example: url(r'foo/bar') will match /foo/bar but also /foo/barf.

Checklist

• PR only contains one change (considered splitting up PR)
• unit-test added (existing unit tests continue to work)
• documentation updated (all doc examples already had $ anchors)
• CHANGELOG.md updated (only for user relevant changes)
• author name in AUTHORS

[codecov]

Codecov Report

Merging #697 into master will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master     #697   +/-   ##
=======================================
  Coverage   95.97%   95.97%           
=======================================
  Files          54       54           
  Lines        2735     2735           
=======================================
  Hits         2625     2625           
  Misses        110      110

Impacted Files	Coverage Δ
example/urls_test.py	100% <ø> (ø)	⬆️

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[codecov]

Codecov Report

Merging #697 into master will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master     #697   +/-   ##
=======================================
  Coverage   95.97%   95.97%           
=======================================
  Files          54       54           
  Lines        2735     2735           
=======================================
  Hits         2625     2625           
  Misses        110      110

Impacted Files	Coverage Δ
example/urls_test.py	100% <ø> (ø)	⬆️

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 189fdfe...8171a86. Read the comment docs.

[sliverc]

Thanks @n2ygk it's great to split out as much as possible from #689 into different PRs. Removed changelog entry though as I think this change is not relevant to current DJA users but only for new users which will start with the example app anyway.

[n2ygk]

...Removed changelog entry though as I think this change is not relevant to current DJA users but only for new users which will start with the example app anyway.

@sliverc Not a big deal, but I expect existing users trying to use the new generateschema functionality will be burned if their code follows the examples and lacks $ or / due to the django simplify_regex bug fix: django/django#11728 which likely won't appear until Django 3.0.

[sliverc]

@n2ygk this is properly better explained in the documentation of generateschema as someone not having based its urls.py on the example app might have the exact same issue as well.