This is the first Express 5.0 beta release, based off 4.17.2 and includes
changes from 5.0.0-alpha.8.

• change:
  • Default "query parser" setting to 'simple'
  • Requires Node.js 4+
  • Use mime-types for file to content type mapping
• deps: array-flatten@3.0.0
• deps: body-parser@2.0.0-beta.1
  • req.body is no longer always initialized to {}
  • urlencoded parser now defaults extended to false
  • Use on-finished to determine when body read
• deps: router@2.0.0-beta.1
  • Add new ?, *, and + parameter modifiers
  • Internalize private router.process_params method
  • Matching group expressions are only RegExp syntax
  • Named matching groups no longer available by position in req.params
  • Regular expressions can only be used in a matching group
  • Remove debug dependency
  • Special * path segment behavior removed
  • deps: array-flatten@3.0.0
  • deps: parseurl@~1.3.3
  • deps: path-to-regexp@3.2.0
  • deps: setprototypeof@1.2.0
• deps: send@1.0.0-beta.1
  • Change dotfiles option default to 'ignore'
  • Remove hidden option; use dotfiles option instead
  • Use mime-types for file to content type mapping
  • deps: debug@3.1.0
• deps: serve-static@2.0.0-beta.1
  • Change dotfiles option default to 'ignore'
  • Remove hidden option; use dotfiles option instead
  • Use mime-types for file to content type mapping
  • deps: send@1.0.0-beta.1