Upgrade node-expat to ensure compatibility with node 10

[Clement134]

Versions of node-expat oldest than 2.3.17 are not compatible with node 10: xmppo/node-expat#190

@c4milo is it possible to merge this pull request and create a new release with all the pending fixes since the latest version ?

[c4milo]

I will cut a new release tomorrow. Thanks!

[3z3qu13l]

@c4milo Would be great to have 0.11.3 ;)

[maximnara]

Hey! Would it be new version with upgraded node support soon?

[c4milo]

I will merge this PR and #159 once Travis passes. It looks like we have some memory leaks, most likely in dependencies.

[Clement134]

@c4milo by memory leaks you refer to this error message: "The following leaks were detected:SharedArrayBuffer, Atomics, WebAssembly" ?

Those are not real memory leaks, but false positive due to differences between nodejs version used for tests, and the nodejs version handled by the version of lab (see hapijs/lab#818). I think the purpose of #159 is precisely to fix that.

[c4milo]

Why does it keep showing up in #159 Travis ouptput if it is fixing it?

[Clement134]

#159 fixes lab false positive on node 8 and 9. But we have to upgrade to at least [email protected] in order to fix the remaining error message (hapijs/lab#837).

[3z3qu13l]

Hello @c4milo ,
Can we merge this PR since the memory leaks is in a dev dependency and not in the code itself ?

[Clement134]

I will merge this PR and #159 once Travis passes. It looks like we have some memory leaks, most likely in dependencies.

I have upgraded lab to the latest version, now all the tests on Travis are green.
@c4milo could you merge this PR ?

[c4milo]

Done. Thanks @Clement134!