Backport 3.0 fixes to 2.0

[dominics]

There might have been some confusion around the bump to requiring PHP 7.1

• PHP 5.6 is still supported on the 2.0 branch, and I'll happily make new releases of 2.0.x versions based off that branch

  • Feel free to open backported bugfix PRs against the 2.0 branch
  • I feel happy to keep the branch open for changes as long as 5.6 is under security support (i.e. we will not accept patches after 31 Dec 2018)
  • We'll take a decision on whether we need a 2.1 branch if a major feature arrives within that timeframe, but I'd strongly encourage any new feature development to target master first

• PHP 7.0 is unsupported because:

  • we've never supported it just because of happenstance and timing
  • ?nullable type hints and void are very nice to have, but not BC -better to break BC once for type hinting than twice

So, that said, there are a couple of errors that the scalar type hints have already cleared up, and there is the Nagle's change on the client socket to backport, if anyone wants to take a stab at them.

[gsouf]

Hi @dominics Looking at your comment, I wonder whether there are known bugs with the library and php 7.0?