prepare 4.1.3 release (OpenAPITools#4052)

Prepare v4.1.2 release (OpenAPITools#3873)

* update samples

* update date

Prepare 4.1.1 release (OpenAPITools#3756)

* 4.1.1 release

* update doc

Prepare 4.1.0 release (OpenAPITools#3597)

* update pom

* update doc

* update version

* add dep for nullable annotaiton

v4.0.3 release (OpenAPITools#3315)

* update snapshot version

* update doc

* comment out haskell servant server test

4.0.2 release (OpenAPITools#3181)

* remove snapshot version

* update stable version

* remove build.gradle sample from relesae script

Prepare 4.0.1 release (OpenAPITools#3041)

* update snapshot version

* update to 4.0.1

4.0.0 release (OpenAPITools#2878)

* remove snapshot version

* update readme

* undo changes to example

* revert apache maven version

* update gradle property

update version (OpenAPITools#2591)

4.0.0-beta2 release (OpenAPITools#2036)