add java version to build

Author: tjake

build.yaml

@@ -5,10 +5,10 @@ architecture:
   - x64
 os:
   - ubuntu/xenial64
+java:
+  - oraclejdk8
 build:
   - script: |
-      . /usr/local/bin/jdk_switcher.sh
-      jdk_switcher use openjdk8
       export MAVEN_HOME=/home/jenkins/.mvn/apache-maven-3.2.5
       export PATH=$MAVEN_HOME/bin:$PATH
       mvn -B install -DskipTests