chore: release 4.0.0

[github-actions]

🤖 I have created a release *beep* *boop*

EDIT: (12/11/2020)

4.0.0 (2020-12-10)

⚠ BREAKING CHANGES

• Remove All API's that are labeled "Remove in 4.0" (Remove All API's that are labeled "Remove in 4.0" #362)
• event: make the event's time property only a string (src(event)!: make the event's time property only a string #330)

Features

• add a constructor parameter for loose validation (#328) (1fa3a05)
• add emitterFactory and friends (#342) (e334b6e)
• add EventEmitter to Emitter and singleton paradigm (25f9c48)
• allow ensureDelivery to be able to ensure delivery on emit (43d9e01)
• introduce Message, Serializer, Deserializer and Binding interfaces (#324) (f3953a9)
• Remove All API's that are labeled "Remove in 4.0" (#362) (875f700)

Bug Fixes

• do not alter an event's data attribute (#344) (1446898)
• extend Node.js IncomingHttpHeaders in our Headers type (#346) (f6be285)
• improve error messages when validating extensions (9f86cfd)
• package.json & package-lock.json to reduce vulnerabilities (132f052)
• package.json & package-lock.json to reduce vulnerabilities (#338) (eca43d9)
• upgrade cloudevents from 3.0.1 to 3.1.0 (#335) (7423acb)
• upgrade uuid from 8.2.0 to 8.3.0 (#317) (6e2390e)

Tests

• implement pending tests leftover from TS rewrite (#315) (b5cf886)

Documentation

• add Emitter logic example (bda8581)
• add ref to CoC and other things (#244) (b3624c2)
• update README with latest API changes (#347) (138de37)
• update README with maintainer names (#337) (0a12146)

Miscellaneous

• add a transition guide. fixes #360 (#363) (79296a8)
• package: Upgrade mocha from 7.1.2 to 8.2.0 (#354) (8205bc9)
• add an automated GH action for releases (#329) (a9114b7)
• tag v3.2.0 as release-v3.2.0 for release-please (#353) (765b81c)
• ci,releases: bump release-please-action to 2.5.5 (#350) (c4afacb)
• Remove commented version import. (#319) (0adcc35)
• typo (#313) (81623ac)
• update release please to the latest release(2.4.1) (#345) (76688c4)
• event: make the event's time property only a string (#330) (6cd310c)
• example: Replaced body parser with express JSON parser (#334) (4779d89)
• add cucumber.js to list of files to lint and /docs to .gitignore (#327) (17d4bc8)
• Update README with correct links for the support specification versions (#321) (73f0bec), closes #320
• Update references of master to main (#316) (4bf2eb8)
• validate cloudevent version agnostic (#311) (8ac3eb0)

This PR was generated with Release Please.