ci: Remove travis.yml and relevant status badge in README.md (#2222)

.travis.yml

@@ -1,30 +0,0 @@
-language: java
-
-sudo: required
-dist: trusty
-
-matrix:
-  include:
-  - jdk: oraclejdk8
-    env: BUILD_JDK=ORACLE_JDK_8
-  - jdk: oraclejdk11
-    env: BUILD_JDK=ORACLE_JDK_11
-  - arch: arm64
-  allow_failures:
-  - env: BUILD_JDK=ORACLE_JDK_11
-
-# https://docs.travis-ci.com/user/languages/java/#maven-dependency-management
-install:
-  - if [ "${TRAVIS_CPU_ARCH}" == "arm64" ]; then
-      sudo apt-get install -y maven openjdk-11-jdk;
-      export JAVA_HOME=/usr/lib/jvm/java-11-openjdk-arm64;
-      export PATH=$JAVA_HOME/bin:$PATH;
-    fi
-  - mvn install -DskipTests=true -Dmaven.javadoc.skip=true -B -V -DminimumPriority=1
-
-after_success:
-  - bash <(curl -s https://codecov.io/bash)
-
-cache:
-  directories:
-  - $HOME/.m2/

README.md

@@ -2,7 +2,6 @@
 
 # Sentinel: The Sentinel of Your Microservices
 
-[![Travis Build Status](https://travis-ci.org/alibaba/Sentinel.svg?branch=master)](https://travis-ci.org/alibaba/Sentinel)
 [![Codecov](https://codecov.io/gh/alibaba/Sentinel/branch/master/graph/badge.svg)](https://codecov.io/gh/alibaba/Sentinel)
 [![Maven Central](https://img.shields.io/maven-central/v/com.alibaba.csp/sentinel-core.svg?label=Maven%20Central)](https://search.maven.org/search?q=g:com.alibaba.csp%20AND%20a:sentinel-core)
 [![License](https://img.shields.io/badge/license-Apache%202-4EB1BA.svg)](https://www.apache.org/licenses/LICENSE-2.0.html)
@@ -179,4 +178,3 @@ If you are using Sentinel, please [add your company here](https://github.com/ali
 ![杭州光云科技](https://www.raycloud.com/images/logo.png)
 ![金汇金融](https://res.jinhui365.com/r/images/logo2.png?v=1.527)
 ![闪电购](http://cdn.52shangou.com/shandianbang/official-source/3.1.1/build/images/logo.png)
-