Update php fpm check to allow ping reply to be configured.

[squaresurf]

No description provided.

[LeoCavaille]

Cool thanks @squaresurf for your contribution.
Just a suggestion: could you add something in the integrations tests to test this new option, for instance set it to blah and test that the can_ping service check returns effectively a CRITICAL status?

[squaresurf]

I've added a test for a bad ping reply. @LeoCavaille would you take a look and make sure I did it correctly? I've not used this test framework before.

[LeoCavaille]

LGTM thanks again 👍

[squaresurf]

@LeoCavaille do you know why the test fails? It doesn't seem to be related to my PR.

[LeoCavaille]

No the PHP-FPM test succeeds which is what matters here. We're currently fixing the CI @degemer is working on it, basically we need to have a different setup for contributors and external forks because they can't use our S3 cache due to credentials issues.
Closing this PR, merged upstream your changes in a rebased commit 552b5d1.
Thanks.

[squaresurf]

Thank you!

[coveralls]

Changes Unknown when pulling 62d75b6 on squaresurf:php-fpm-ping-reply into ** on DataDog:master**.