add oncrpc4j build script

oncrpc4j-build.yaml

+variables:
+  MAVEN_CLI_OPTS: "--batch-mode --errors --fail-at-end --show-version -DinstallAtEnd=true -DdeployAtEnd=true"
+  REPO_NAME: oncrpc4j
+
+image: maven:3.6.3-openjdk-11
+
+# Cache downloaded dependencies and plugins between builds.
+# To keep cache across branches add 'key: "$CI_JOB_NAME"'
+cache:
+  key: "CI_JOB_NAME"
+  paths:
+    - .m2/repository
+
+build:
+  stage: build
+  script:
+    - mvn $MAVEN_CLI_OPTS clean package
+
+  artifacts:
+    reports:
+      junit:
+        - "**/target/surefire-reports/TEST-*.xml"
+        - "**/target/failsafe-reports/TEST-*.xml"