fix(deps): update dependency express to v4.15.5

This Merge Request updates dependency express from v4.15.4 to v4.15.5

Commits

expressjs/express

4.15.5

• ea3d605 4.15.5
• 40435ec deps: serve-static@1.12.6
• 7137bf5 deps: send@0.15.6
• bd1672f deps: finalhandler@~1.0.6
• 9395db4 deps: debug@2.6.9
• 19a2eeb tests: check render error without engine-specific message
• d7da225 build: should@13.1.0
• 961dbff deps: serve-static@1.12.5
• 9e0fa7f deps: send@0.15.5
• 9e067ad deps: fresh@0.5.2
• de5fb62 deps: update example dependencies
• b208b24 build: should@13.0.1
• 78e5510 build: mocha@3.5.3
• 48817a7 build: remove minor pin for nightly

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This MR has been generated by Renovate Bot.