route del throw error when register

[moonavw]

https://github.com/stewartml/express-decorators/blob/313afc90951fea5ae3ef2206e2525d46bcf2b919/src/lib/index.ts#L74

the 'del' throws error during register, since router['del'] is undefined, I am using express 4.17.1

It should be route('delete', path, middleware)