Documentation:

• Added documentation on features of fetch which are not polyfilled. -- https://github.com/github/fetch/pull/734

Bug fixes:

• Empty header names used to not throw an error which was not compliant with the specification. They now throw a TypeError, the same as Chrome, Firefox and Safari do. -- https://github.com/github/fetch/pull/684

• Changed the default status text of a response to align with the specification, the default is now an empty string. -- https://github.com/github/fetch/pull/698

• We now allow exclamation mark as valid header character to align with the specification -- https://github.com/github/fetch/pull/745

• We no longer convert application/octet-stream responses into Blobs if the browser supports ArrayBuffers -- https://github.com/github/fetch/pull/752

• Added compatibility for fetch-mock -- https://github.com/github/fetch/pull/736

• Making a fetch request with an empty string for the url no longer throws a DOMException error in Internet Explorer -- https://github.com/github/fetch/pull/619

• Fixed another Internet Explorer bug to make sure all resolved fetch promises will trigger their promise chains -- https://github.com/github/fetch/pull/575