Support `enableDocPage` option

What's done:

1. I've tweaked dependencies versions a little bit. Here's how I usually think about deps: if major version is 0, it's possible to get breaking changes with some updates, so it's safer either to freeze on a particular version or to have patches updated automatically. That is why I prefer to have `~` prefix for `vow`. If the package is stable, it's ok to have `^` for development tools and for packages you are sure about.

2. `enableDocPage` option is going to replace `disableDocPage`. So I added support for the first one and deprecated the last one.
Let's do it in red.

It seems we need [colors module](https://www.npmjs.org/package/colors) because we show warnings in two places.