Update dependency express to v4.15.4

[renovate-tests]

This Pull Request updates dependency express from v4.15.3 to v4.15.4

Commits

expressjs/express

4.15.4

• a4bd437 4.15.4
• a50f109 deps: serve-static@1.12.4
• e2d725e deps: send@0.15.4
• e006622 lint: remove all unused varaibles
• 44881fa docs: update collaborator guide for lint script
• 1dbaae5 deps: update example dependencies
• 56e90e3 lint: add eslint rules that cover editorconfig
• 713d2ae tests: fix incorrect should usage
• e0aa8bf build: mocha@3.5.0
• 85770a7 deps: finalhandler@~1.0.4
• daf66be examples: fix path join in ejs example
• b2af101 build: ejs@2.5.7
• 3eb16c2 deps: depd@~1.1.1
• 582381b deps: proxy-addr@~1.1.5
• 5e16f40 examples: use 1-based visitor count in cookie-sessions
• 43dff4c docs: fix GitHub capitalization
• 04beebb build: Node.js@6.11
• 1adee79 deps: update example dependencies
• bd5951e deps: debug@2.6.8
• deffce5 deps: qs@6.5.0
• 48777dc build: mocha@3.4.2
• 9467a39 build: Node.js@7.10
• 9f019c8 examples: add comment about Redis install in examples
• cf37240 examples: fix reference error in view-constructor
• 60f87f8 examples: fix posts link in route-separation example
• fde8f64 examples: fix route in params example

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This PR has been generated by Renovate Bot.