fix: fix typescript compilation

[JustinBeckwith]

Fixes #287. There are a few places where we accept File type objects, which is defined in google-cloud/storage. The package is only needed for types, so it's installed as a devDependency. However - this means the types for storage aren't shipped with the module, which causes compilation to fail for consumers of the package. This change dumps the File type for now in favor of any, and adds an install test to verify basic compilation works after an npm pack.

[JustinBeckwith]

@googleapis/node-team this is an interesting problem, and I'm interested in y'alls opinions :)

[jkwlui]

Let’s define an interface that contains the properties of File that this library needs. Since we only intend to access the relevant properties and we’re not creating a new File object, we should just provide the interface and note in the docs that a File object can be provided.

[ofrobots]

I see this problem with TypeScript code once per fortnight. The real solution here would be a way to tell the package installer this info: "If you install this package as a devDependency of a top-level install, you also need to install these other devDependencies of mine".

IOW, we need a transitiveDevDependencies section in package.json that somehow npm could respect. It might be worth engaging with TypeScript and npm folks on this.