Migrate from Travis CI to GitLab CI

.gitlab-ci.yml

+image: openjdk:8-jdk-slim
+
+stages:
+  - test
+  - deploy
+
+variables:
+  GRADLE_OPTIONS: --no-daemon --info --stacktrace --warning-mode=all
+
+cache:
+  paths:
+    - .gradle/wrapper
+    - .gradle/caches
+
+before_script:
+  - export GRADLE_USER_HOME=`pwd`/.gradle
+
+tests:
+  stage: test
+  script: ./gradlew ${GRADLE_OPTIONS} check
+
+tests:jdk-11:
+  extends: tests
+  image: openjdk:11-jdk-slim
+
+tests:jdk-17:
+  extends: tests
+  image: openjdk:17-jdk-slim
+
+publish:
+  stage: deploy
+  script:
+    - openssl aes-256-cbc -pass "env:ENCRYPTION_PASSWORD" -d -in secring.gpg.enc -out secring.gpg
+    - openssl aes-256-cbc -pass "env:ENCRYPTION_PASSWORD" -d -in pubring.gpg.enc -out pubring.gpg
+    - openssl aes-256-cbc -pass "env:ENCRYPTION_PASSWORD" -d -in gradle.properties.enc -out gradle.properties
+    - ./gradlew ${GRADLE_OPTIONS} publish
+  only:
+    - master@general/stups/tla2bAST
+    - develop@general/stups/tla2bAST

.travis.yml

-language: java
-script: ./gradlew createJar check publish
-
-before_install:
-- openssl aes-256-cbc -pass pass:$ENCRYPTION_PASSWORD -in secring.gpg.enc -out secring.gpg
-  -d
-- openssl aes-256-cbc -pass pass:$ENCRYPTION_PASSWORD -in pubring.gpg.enc -out pubring.gpg
-  -d
-- openssl aes-256-cbc -pass pass:$ENCRYPTION_PASSWORD -in gradle.properties.enc -out
-  gradle.properties -d
-
-env:
-  global:
-  - secure: RSWp6NRFm5iSK76fm6Ms1FLyUKMKhXt1JrUAQ6x558R73mT7SUvdKbBn9Ffh+TiNO6JVsma3KFoHvYnx8Ys6OGipyXW8g2DKiyg3jm2im4HTtxJqpp7Rls0gm0jGpjOOLwkWl719DZLC6+cPoUuGWtAk8FbowkBz1uWySnJSltI=
-  - secure: COBSC/26p1nTF3rZgSdy1iz7biCnwULsTrc5R6HvcZwlve8jtMej6Nr0oecjcAFvZaaKrEZTSSRtI3W5gwC5Jxpffgrf0ZmJPXg1BPwamve97s7Gyhfb1wyJWRPOkt71AVqBXe6yvSnjm5jeExsE+mUIpurmG9eUaWGDU8gXRv0=
-  - secure: G0dFwNmRNpxhqUYJyx+Ua7/Grb+AMLCipOuysyeR6ImRPHCwI1i5Hd5pPnRqq30psTiWllFc5eijqVvx19bLIUARG0pH7rUBcKNeL0R9THpJcflOO3NNAx5wF01jpuK0CnkDfnz90FDpjvB6vPi2NCInMKypuozxMsMZVnhzm90=

README.md

 # tla2bAST
 
-[![Build Status](https://travis-ci.org/hhu-stups/tla2bAST.svg)](https://travis-ci.org/hhu-stups/tla2bAST)
+[![GitLab CI](https://gitlab.cs.uni-duesseldorf.de/general/stups/tla2bAST/badges/master/pipeline.svg)](https://gitlab.cs.uni-duesseldorf.de/general/stups/tla2bAST/pipelines)