[WIP] Test JDK12 (#5426)

* test-jdk12

* Add right version in gh-actions

.github/workflows/deployment.yml

@@ -45,7 +45,7 @@ jobs:
     - name: Set up JDK
       uses: actions/setup-java@v1
       with:
-        java-version: 11.0.4
+        java-version: 12.0.2
     - name: Download jpackage
       # We need to download jpackage from https://jdk.java.net/jpackage/
       run: |

.travis.yml

@@ -1,6 +1,6 @@
 language: java
 jdk:
-  - openjdk11
+  - openjdk12
 
 # we test at Ubuntu Trusty (Ubuntu 14.04 LTS)
 # see https://docs.travis-ci.com/user/trusty-ci-environment/

build.gradle

@@ -47,8 +47,8 @@ apply from: 'eclipse.gradle'
 
 group = "org.jabref"
 version = "5.0.0"
-sourceCompatibility = 11
-targetCompatibility = 11
+sourceCompatibility = 12
+targetCompatibility = 12
 mainClassName = "$moduleName/org.jabref.JabRefLauncher"
 
 // TODO: Ugly workaround to temporarily ignore build errors to dependencies of latex2unicode