Replace Travis-CI badge with GitHub Action's

Author: harawata

README.md

@@ -1,7 +1,7 @@
 MyBatis SQL Mapper Framework for Java
 =====================================
 
-[![Build Status](https://travis-ci.org/mybatis/mybatis-3.svg?branch=master)](https://travis-ci.org/mybatis/mybatis-3)
+[![build](https://github.com/mybatis/mybatis-3/workflows/Java%20CI/badge.svg)](https://github.com/mybatis/mybatis-3/actions?query=workflow%3A%22Java+CI%22)
 [![Coverage Status](https://coveralls.io/repos/mybatis/mybatis-3/badge.svg?branch=master&service=github)](https://coveralls.io/github/mybatis/mybatis-3?branch=master)
 [![Maven central](https://maven-badges.herokuapp.com/maven-central/org.mybatis/mybatis/badge.svg)](https://maven-badges.herokuapp.com/maven-central/org.mybatis/mybatis)
 [![Sonatype Nexus (Snapshots)](https://img.shields.io/nexus/s/https/oss.sonatype.org/org.mybatis/mybatis.svg)](https://oss.sonatype.org/content/repositories/snapshots/org/mybatis/mybatis/)