Fix readme

Author: akarnokd

README.md

@@ -1,11 +1,11 @@
 # RxJavaSwing
 
 
-<a href='https://travis-ci.org/akarnokd/RxJavaSwing/builds'><img src='https://travis-ci.org/akarnokd/RxJavaSwing.svg?branch=master'></a>
-[![codecov.io](http://codecov.io/github/akarnokd/RxJavaSwing/coverage.svg?branch=master)](http://codecov.io/github/akarnokd/RxJavaSwing?branch=master)
+<a href='https://travis-ci.org/akarnokd/RxJavaSwing/builds'><img src='https://travis-ci.org/akarnokd/RxJavaSwing.svg?branch=3.x'></a>
+[![codecov.io](http://codecov.io/github/akarnokd/RxJavaSwing/coverage.svg?branch=3.x)](http://codecov.io/github/akarnokd/RxJavaSwing?branch=3.x)
 [![Maven Central](https://maven-badges.herokuapp.com/maven-central/com.github.akarnokd/rxjava3-swing/badge.svg)](https://maven-badges.herokuapp.com/maven-central/com.github.akarnokd/rxjava3-swing)
 
-RxJava 2.x: [![RxJava 2.x](https://maven-badges.herokuapp.com/maven-central/io.reactivex.rxjava2/rxjava/badge.svg)](https://maven-badges.herokuapp.com/maven-central/io.reactivex.rxjava2/rxjava)
+RxJava 3.x: [![RxJava 3.x](https://maven-badges.herokuapp.com/maven-central/io.reactivex.rxjava3/rxjava/badge.svg)](https://maven-badges.herokuapp.com/maven-central/io.reactivex.rxjava3/rxjava)
 
 Bridge between Java 6 Swing (GUI) events and RxJava 3 + a scheduler for the swing event dispatch thread.