今天 Retrofit2.2最新版本发布，以下为此次更新内容：
Version 2.2.0 (2017-02-21)
RxJava 2.x is now supported with a first-party 'adapter-rxjava2' artifact.
（支持rxJava2了, 使用适配器：compile 'com.squareup.retrofit2:adapter-rxjava2:2.2.0'）New: @QueryName annotation allows creating a query parameter with no '=' separator or value.
New: Support for messages generated by Protobuf 3.0 or newer when using the converter for Google's protobuf.
New: RxJava 1.x call adapter now correctly handles broken subscribers whose methods throw exceptions.
New: Add toString() implementations for Response and Result.
New: The Moshi converter factory now offers methods for enabling null serialization and lenient parsing.
New: Add createAsync() to RxJava 1.x call adapter factory which executes requests using Call.enqueue() using the underlying HTTP client's asynchronous support.
New: NetworkBehavior now allows setting an error percentage and returns HTTP errors when triggered.
HttpException has been moved into the main artifact and should be used instead of the versions embedded in each adapter (which have been deprecated).
Promote the response body generic type on CallAdapter from the adapt method to the enclosing class. This is a source-incompatible but binary-compatible change which is only relevant if you are implementing your own CallAdapters.
Remove explicit handling of the now-defunct RoboVM platform.
Fix: Close response on HTTP 204 and 205 to avoid resource leak.
Fix: Reflect the canceled state of the HTTP client's Call in Retrofit's Call.
Fix: Use supplied string converters for the String type on non-body parameters. This allows user converters to handle cases such as when annotating string parameters instead of them always using the raw string.
Fix: Skip a UTF-8 BOM (if present) when using the converter for Mosh.
