Pass the strlen to the readCallback as was expected

[rullzer]

So turns out I was to quick with #8

Fixed now
And adjusted the tests to actually check for this

[coveralls]

Coverage remained the same at 95.413% when pulling 8c45c9a on rullzer:master into e1b5ac1 on icewind1991:master.

[rullzer]

I have no idea why php <7 is failing

[rullzer]

Ok turns out php <7 always reads the chunk size and does other magic in fread.

[icewind1991]

you can add a condition for the php version in the test case.

As long as the callback actually gets the number of bytes read it doesn't matter that those values depend on php version