ZOOKEEPER-3919: Added ARM64 support to Travis-CI

1. Added ARM64 support with jdk 11
2. Installed maven if architecture is ARM64

Signed-off-by: odidev <odidevpuresoftware.com>

Author: odidev <odidev@puresoftware.com>

Reviewers: Enrico Olivelli<eolivelli@apache.org>, Damien Diederen <ddiederen@apache.org>, Christopher Tubbs, Martin Grigorov

Closes #1433 from odidev/zookeeper_ARM64

.travis.yml

@@ -6,6 +6,9 @@ matrix:
       jdk: openjdk8
     - os: linux
       jdk: openjdk11
+    - os: linux
+      arch: arm64
+      jdk: openjdk11
     - os: linux
       arch: s390x
       jdk: openjdk11
@@ -25,6 +28,11 @@ addons:
     packages:
     - libcppunit-dev
 
+install:
+  - if [ "${TRAVIS_CPU_ARCH}" == "arm64" ]; then
+     sudo apt-get install maven;
+    fi
+
 script: mvn clean apache-rat:check verify -DskipTests spotbugs:check checkstyle:check -Pfull-build
 
 branches: