MDL-75757 phpunit: Add some tolerance to a few failing assertions
Recently, PHPUnit (all versions) did some changes about how the
comparators worked and this has caused some float comparisons
to stop working.
We need to move them to assertEqualsWithDelta(), allowing a small
tolerance to workaround the floats comparison problem.
0.00001 has been decided. And applied to all the similar assertions
within the unittest function, so if more cases are added to them
better be copied with the agreed tolerance.