reset() does not reset high-resolution timer

[novemberborn]

• Lolex version : 2.7.4

What did you expect to happen?

reset() resets the high-resolution timer.

What actually happens

The high-resolution timer is not reset.

How to reproduce

const clock = lolex.install()
clock.now === 0
clock.tick(20)
clock.hrNow === 20
clock.reset()
clock.now === 0
clock.hrNow === 20

[benjamingr]

PR welcome, otherwise I can work on this in October happily :)