Consider updating Express integration docs to use `express.json()` instead of `body-parser`
Huh, apparently for 5 years (since v4.16.0) you can do `express.json()` instead of also installing `body-parser`. Maybe we should do that in the standalone server and in our docs around using expressMiddleware.

On the other hand, perhaps it's nicer to directly depend on your dependencies so you can get bug fixes via direct upgrades rather than transitive upgrades, so maybe we should leave it as is.

See https://community.apollographql.com/t/is-it-necessary-to-install-bodyparser/5163