Move debug type defns into devDependencies

[whymarrh]

This PR moves @types/debug into devDependencies as it shouldn't be needed in dependencies

[coveralls]

Coverage remained the same at 95.092% when pulling 52f400a on whymarrh:types-dependency into 1fd2515 on blakeembrey:master.

[blakeembrey]

I'm ok, I'd like to keep the @types with its dependency. You never know when the type may be accidentally exported because the tooling unfortunately doesn't exist for that kind of checking.

[whymarrh]

You never know when the type may be accidentally exported because the tooling unfortunately doesn't exist for that kind of checking.

Could I bother you for a clarification on this? I don't understand the situation you're describing.

[blakeembrey]

export const str: string;

The type is now exported. It can happen just as easily if a type (e.g. function signature) were exported from debug. Not saying this would happen, but I'd avoid to have to make every person and myself remember to check this since there's no tooling to verify it isn't happening.

[whymarrh]

Ah, yes, you're talking about types you depend on for your own type defns. Thanks for the clarification.