Retry failed dummyserver tests once

[pquentin]

Closes #1595

[codecov-io]

Codecov Report

Merging #1718 into master will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master    #1718   +/-   ##
=======================================
  Coverage   99.65%   99.65%           
=======================================
  Files          22       22           
  Lines        2006     2006           
=======================================
  Hits         1999     1999           
  Misses          7        7

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[sethmlarson]

Looks good, just one question.

[sethmlarson]

I've never seen this construction before, where is it documented? Must it be named pytestmark?

[pquentin]

Yes: http://doc.pytest.org/en/latest/example/markers.html#marking-whole-classes-or-modules

I agree that it's quite obscure, which is why I added the comment. But it's way more convenient than marking every class or every test. Another option is do this for all tests, not only dummyserver tests: we could simply use a command-line option then.

[sethmlarson]

Today I learned! This looks good ready to go then. :)