This release brings referential transparency to the Req type by
making it an immutable builder of RequestBuilder — that's right,
Spring fans, it's a factory-factory.
Previously Req was a type alias for the RequestBuilder class of
the underlying async-http-client library. This class is unfortunately
mutable, leading to unexpected behavior when an instance is reused.
For programs that refer to RequestBuilder explicitly, this version
of Dispatch provides an implicit conversion from Req to
RequestBuilder. This conversion reintroduces mutable behavior and is
is annotated as deprecated.
The method Req.build is provided for backwards compatibility, but is
deprecated. Use toRequest or toRequestBuilder to access the
underlying interfaces explicitly.
This release also removes the dispatch.Promise-bridging methods that
were deprecated in version 0.10.