Move unexported dependencies on @types to devDependencies

[merlinnot]

Description

Whereas @types/express is actually a dependency, as it's types are re-exported, the other three are only used internally - they are therefore not included and used in built package - an easy find in lib can confirm that. I moved it to devDependencies, so it's not installed together with the package, making installation more performant - which is important especially in FaaS environments.

Code sample

Not relevant.

[merlinnot]

@thechenky

[thechenky]

This is what broke our v3.0.0 release - these types need to be in dependencies.

[merlinnot]

Are you sure all of these are required, not only @types/express? It would make perfect sense, as I described in the PR description.

I just tested it locally, doing npm pack, initialising an empty project, linking it locally, compiling - all worked just fine.

[thechenky]

Ah yes, you're right, I didn't notice that @types/express was still under dependencies. I think that's the only one we need. I just cloned your fork to confirm this. When I remove @types/express I get compile errors, same as what we saw when releasing v3.0.0, but with it back in, no errors. Going to run integration tests now.

[thechenky]

Oh actually one nit - the ordering is a bit off in the package.json - chai should be above chai-as-promised and there's a couple others.

[thechenky]

Integration tests passed. This is good to go in!