add ember-cli-preprocess-registry to deps

[kellyselden]

Used https://github.com/ember-fastboot/ember-cli-fastboot/blob/master/index.js#L18

[rwjblue]

Not sure we should actually add the dep here. We need to require ember-cli's own version of this or we are going to cause many issues down the line when we update it in ember-cli.

[kellyselden]

@rwjblue Does ember-cli re-export it that you know of? This was causing failures when I tried to npm link ember-cli.

[kratiahuja]

Isn't ember-cli-preprocess-registry standalone? I thought ember-cli depends on it as well.

[rwjblue]

It does, I've just been working on some breaking changes (for ember-cli-preprocess-registry@4) and dealing with the interactions between the two different versions (one from ember-cli-fastboot and one from ember-cli) will be difficult...

[kellyselden]

@rwjblue We could solve this via a simple reexport in ember-cli right?

[kratiahuja]

I am fine with one source of truth (even if it means ember-cli).