Add CI script

Change-Id: I10f72fb3d31b4b6420bff192a179069994b43f7e
diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
new file mode 100644
index 0000000..24d366d
--- /dev/null
+++ b/.gitlab-ci.yml
@@ -0,0 +1,29 @@
+image: eclipse-temurin:17
+
+stages:
+    - build
+
+# Disable the Gradle daemon for Continuous Integration servers as correctness
+# is usually a priority over speed in CI environments. Using a fresh
+# runtime for each build is more reliable since the runtime is completely
+# isolated from any previous builds.
+variables:
+  GRADLE_OPTS: "-Dorg.gradle.daemon=false"
+
+before_script:
+  - GRADLE_USER_HOME="$(pwd)/.gradle"
+  - export GRADLE_USER_HOME
+
+build:
+  stage: build
+  script:
+    - ./gradlew --build-cache build
+  artifacts:
+    paths:
+      - app/build/libs/korapxml2conllu.jar
+  cache:
+    key: "$CI_COMMIT_REF_NAME"
+    policy: push
+    paths:
+      - build
+      - .gradle