Add configurable body-parser limit

[Vasilii Ermilov]

Hello, recently I was testing a few apps with your utility and came across the fact that default body-parser limit (https://github.com/expressjs/body-parser#limit) is too small for handling some requests, especially while dealing with single-page applications.
I suggest adding body-parser's limit option to config.

[Lewis]

Thanks for the contribution, makes a lot of sense to increase the body limit for full DOM capture for SPA