The one where we finally released v4.0.0

*** This release contains many breaking changes ***

Big, breaking changes
#257 added context propagation to methods (thx @ar3s3ru for the massive PR)
#258 contains a list of breaking changes - see the PR for details
#275 added more nullable fields

...and many many more....

See here for a complete list of all commits and changes since the last 3.x release