HHVM 3.30 dropped support for PHP

[DanielRuf]

https://travis-ci.org/singpolyma/openpgp-php/builds/525386351

https://travis-ci.org/singpolyma/openpgp-php/jobs/525386354#L508

HipHop VM 4.2.0 (rel)

https://hhvm.com/blog/2018/09/12/end-of-php-support-future-of-hack.html

HHVM v3.30 will be the last release series where HHVM aims to support PHP. The key dates are:

2018-12-03: branch cut: expect PHP code to stop working with master and nightly builds after this date
2018-12-17: expected release date for v3.30.0
2019-01-28: expected release date for v4.0.0, without PHP support
2019-11-19: expected end of support for v3.30