* [dart] Fix authentication so all forms of Swagger 2.0 authentication work
* Run changes on petstore examples
* Amend dart2 generated README to cover basic authentication
* Amend dart2 generated README to cover authentication methods
* [dart] Fix authentication so all forms of Swagger 2.0 authentication work
* Run changes on petstore examples
* fix: set fields to null if json value is null.
* rebuild dart2 petstore
* rebuild dart petstore
* rebuild petstore
* [DART]fix: set fields to null if json value is null.
* Add an option for Dart2
* add dart2 samples, update travis
* fix dart installation
* Upper constraints on the SDK version
* Update dependencies
* supportDart2 option can now be passed through --additional-properties
* Update petstore tests
* Update dart2-petstore.sh
* Running tests on Dart VM
* Fixed JSON deserialization bugs
* Fixed missing initialization of postBody
* Run bin/dart2-petstore.sh to regenerate libraries
* Update pom.xml
* Added SDK version constraints in pubspec.mustache
* Run bin/dart2-petstore.sh to regenerate libraries
* move dart2 test to the end
