Use start/end anchors in matchStrings() regex

[jmikola]

I came across this when creating two similarly named collections in a Sculpin deployment ("posts" and "posts2" used source directories "_posts" and "_posts2", respectively). I found that the data collector for "posts" contained sources from both directories and ultimately traced it back to logic in AntPathMatcherTest.

I wasn't familiar with the Ant pattern syntax before this PR, but I think the regex anchoring is correct per the syntax definition in AntPathMatcher in the Spring API docs. I didn't come across any documentation that suggested path components should not be matched in their entirety. That said, matchStrings() is called from a few places so it'd be prudent to confirm this doesn't inadvertently break other use cases.

In order to test this, I had to make some additional changes to allow a newer version of PHPUnit. I attempted to do so without breaking support for older PHP versions.

As a side note, if you're looking to improve the test coverage for the AntPathMatcher class, it may be worth pulling in additional test cases from AntPathMatcherTests.java.

[simensen]

Thank you so much for looking into this. I have a few questions and comments. If you have time to do a bit more digging (like, if you already have some environment set up where you can look at this a bit more) that would be awesome.

Rooting the regular expression might be the right call anyway, but it seems like that should actually be required. It seems more likely based on what I recall that maybe Sculpin isn't adding the /** suffix to the path. This could still be an issue with this library, but in that case it might be in isPattern.