update Drone CI config, switch to OpenJDK on Travis

.drone.yml

@@ -1,15 +1,7 @@
 kind: pipeline
 name: java8
 
-clone:
-  disable: true
-
 steps:
-- name: clone
-  image: plugins/git
-  settings:
-    depth: 10
-    skip_verify: true
   - name: test
     image: maven:3-jdk-8-alpine
     commands:
@@ -19,15 +11,7 @@ steps:
 kind: pipeline
 name: java11
 
-clone:
-  disable: true
-
 steps:
-- name: clone
-  image: plugins/git
-  settings:
-    depth: 10
-    skip_verify: true
   - name: test
     image: maven:3-jdk-11-slim
     commands:

.travis.yml

@@ -1,7 +1,7 @@
 language: java
 jdk:
-  - oraclejdk8
+  - openjdk8
-  - oraclejdk11
+  - openjdk11
 install: true
 addons:
   sonarcloud:
@@ -13,4 +13,4 @@ cache:
     - '$HOME/.m2/repository'
     - '$HOME/.sonar/cache'
 script:
-  - mvn -P jacoco clean package sonar:sonar
+  - if [ "$TRAVIS_JDK_VERSION" == "openjdk11" ]; then mvn -P jacoco clean package sonar:sonar; else mvn clean test; fi