Don't push code coverage when on hhvm environment.

Signed-off-by: crynobone <crynobone@gmail.com>
Merge branch '2.1' into 2.2
Convert multi-dimensional array to single level array when using
`Orchestra\Support\Str::replace()` method.

Signed-off-by: crynobone <crynobone@gmail.com>
Merge branch '2.2'