Use docker in Travis CI
diff --git a/.travis.yml b/.travis.yml
index b7d8d16..77af19b 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,15 +1,25 @@
-language: java
-jdk:
- - openjdk8
- - openjdk9
- - openjdk10
- - openjdk11
- - openjdk12
-#before_script:
-# - pip install --user codecov
+language: minimal
-#after_success:
-# - codecov
+services:
+ - docker
-#addons:
-# srcclr: true
+jobs:
+ include:
+ - env: DOCKER_IMAGE=maven:3.6.2-jdk-8
+ - env: DOCKER_IMAGE=maven:3.5.4-jdk-9 # There are no newer images with Maven for this JDK
+ - env: DOCKER_IMAGE=maven:3.6.0-jdk-10 # There are no newer images with Maven for this JDK
+ - env: DOCKER_IMAGE=maven:3.6.2-jdk-11
+ - env: DOCKER_IMAGE=maven:3.6.2-jdk-12
+ - env: DOCKER_IMAGE=maven:3.6.2-jdk-13
+ - env: DOCKER_IMAGE=maven:3.6.2-jdk-14
+
+install:
+ - docker pull "${DOCKER_IMAGE}"
+
+script:
+ - docker run
+ --env "_JAVA_OPTIONS=-Djdk.net.URLClassPath.disableClassPathURLCheck=true"
+ --volume "$PWD":/usr/src/
+ --workdir /usr/src/
+ --rm
+ "${DOCKER_IMAGE}" mvn clean test -B