Adds GitLab CI for tests and checks

variables:

  GIT_STRATEGY: clone

  METRICS_LIB_VERSION: "2.6.2"

  JAVA_TOOL_OPTIONS: "-Dfile.encoding=UTF-8"

stages:

 - test

test:

 stage: test

 image: debian:buster

 script:

  - apt update

  - apt -y install default-jdk ant ivy git curl

  - git submodule init

  - git submodule update

  - mkdir lib

  - mkdir tmp

  - pushd tmp

  - curl https://dist.torproject.org/metrics-lib/$METRICS_LIB_VERSION/metrics-lib-$METRICS_LIB_VERSION.tar.gz | tar xzf -

  - popd

  - mv tmp/metrics-lib-$METRICS_LIB_VERSION/generated/dist/metrics-lib-$METRICS_LIB_VERSION-thin.jar lib

  - ant -lib /usr/share/java resolve

  - ant test

  - ant checks