update badges in readme

README.md

@@ -2,13 +2,13 @@
 
 > Click on badges to follow links:
 
-Stable v0.21 | Stable v0.22 | Dev | Coverage | Documentation
+Stable v0.22 | Stable v0.23 | Dev | Coverage | Documentation
 --------------|-------------|-------------|-----|---------
-[![build-0-21]][travis-url] | [![build-0-22]][travis-url] | [![build-master]][travis-url] <br> [![commits-url]][contributors-url] <br> [![issues-time]][issues-url] | [![codecov-io]][codecov-url] <br> [![issues-open]][issues-url] | [![cjl-slack-badge]][cjl-slack] <br> [![caesar-docs]][cjl-docs-url] <br> [![dfg-docs]][dfg-docs-url]
+[![build-0-22]][travis-url] | [![build-0-23]][travis-url] | [![build-master]][travis-url] <br> [![commits-url]][contributors-url] <br> [![issues-time]][issues-url] | [![codecov-io]][codecov-url] <br> [![issues-open]][issues-url] | [![cjl-slack-badge]][cjl-slack] <br> [![caesar-docs]][cjl-docs-url] <br> [![dfg-docs]][dfg-docs-url]
 
 [travis-url]: https://travis-ci.org/JuliaRobotics/IncrementalInference.jl
 [build-master]: https://travis-ci.org/JuliaRobotics/IncrementalInference.jl.svg?branch=master
-[build-0-21]: https://travis-ci.org/JuliaRobotics/IncrementalInference.jl.svg?branch=release/v0.21
+[build-0-23]: https://travis-ci.org/JuliaRobotics/IncrementalInference.jl.svg?branch=release/v0.23
 [build-0-22]: https://travis-ci.org/JuliaRobotics/IncrementalInference.jl.svg?branch=release/v0.22
 
 [codecov-io]: https://codecov.io/github/JuliaRobotics/IncrementalInference.jl/coverage.svg?branch=master