Allow express-handlebars to take an array of views

[hatemjaber]

the proposed change is a first pass at allowing express-handlebars to accept an array of views directories. I'm not sure if the project maintainer(s) are open to the feature. I have tested this with an array of paths and a single string and it works as expected.

[UziTech]

I have finally gotten around to moving this repo to https://github.com/express-handlebars/express-handlebars/ any new development will be done on that repo.

If you could move this PR to that repo I could take a look at merging it.