Fix parsers.re doing only partial string match

[youtux]

This PR make sure that parsers.re does a fullmatch of the re, rather than ignoring non-matching characters at the end of the string.
All the other parsers already work this way, there is no reason for parsers.re not to.

Checklist

• Merge Reusable step functions #534 first

[codecov]

Codecov Report

Merging #539 (fc6333a) into master (e24aee0) will increase coverage by 0.02%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master     #539      +/-   ##
==========================================
+ Coverage   92.43%   92.46%   +0.02%     
==========================================
  Files          49       49              
  Lines        1679     1685       +6     
  Branches      208      208              
==========================================
+ Hits         1552     1558       +6     
  Misses         90       90              
  Partials       37       37              

Impacted Files	Coverage Δ
pytest_bdd/parsers.py	85.96% <100.00%> (ø)
tests/args/regex/test_args.py	100.00% <100.00%> (ø)

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[The-Compiler]

FWIW this broke a couple of tests for me where I used trailing periods: qutebrowser/qutebrowser@418f91d

Is that intended? I'm guessing yes, but I have no idea how other Gherkin parsers handle this.

[youtux]

It is expected to break a few steps indeed, I will release a new major version for this.

maybe I’ll mention in the release notes how to migrate to this, although I assume that if you use regex, you know how to consume all characters at the end of the string.