Prefer Time.now over Time.new

Currently, using GitHub search:

* Time.new has [376,997 code results](https://github.com/search?l=ruby&q=time.now&source=c&type=Code)
* Time.now has [18,858 code results](https://github.com/search?l=ruby&q=time.new&source=c&type=Code)

The ratio of new:now is approximately 20:1.