Update README.md (#915)

Fixing the build, javadoc, and maven badges.

README.md

@@ -1,9 +1,9 @@
 # Amazon Ion Java
 A Java implementation of the [Ion data notation](https://amazon-ion.github.io/ion-docs).
 
-[![Build Status](https://travis-ci.org/amazon-ion/ion-java.svg?branch=master)](https://travis-ci.org/amazon-ion/ion-java)
-[![Maven Central](https://maven-badges.herokuapp.com/maven-central/com.amazon.ion/ion-java/badge.svg)](https://maven-badges.herokuapp.com/maven-central/com.amazon.ion/ion-java)
-[![Javadoc](https://javadoc-badge.appspot.com/com.amazon.ion/ion-java.svg?label=javadoc)](http://www.javadoc.io/doc/com.amazon.ion/ion-java)
+![Build Status](https://github.com/amazon-ion/ion-java/actions/workflows/main.yml/badge.svg)
+![Maven Central Version](https://img.shields.io/maven-central/v/com.amazon.ion/ion-java)
+[![Javadoc](https://javadoc.io/badge2/com.amazon.ion/ion-java/javadoc.svg)](https://javadoc.io/doc/com.amazon.ion/ion-java) 
 
 ## Setup
 This repository contains a [git submodule](https://git-scm.com/docs/git-submodule)