use jdk 11 in docker for ci build

.editorconfig

@@ -15,3 +15,7 @@ charset = utf-8
 [*.py]
 indent_style = space
 indent_size = 4
+
+[{Makefile,**.mk}]
+# Use tabs for indentation (Makefiles require tabs)
+indent_style = tab

Jenkinsfile

@@ -1,7 +1,7 @@
 #!groovy
 
 // Keep the version in sync with the one used in pom.xml in order to get correct syntax completion.
-@Library('github.com/cloudogu/ces-build-lib@59d3e94')
+@Library('github.com/cloudogu/ces-build-lib@1.35.1')
 import com.cloudogu.ces.cesbuildlib.*
 
 node('docker') {
@@ -103,8 +103,7 @@ node('docker') {
 String mainBranch
 
 Maven setupMavenBuild() {
-  // Keep this version number in sync with .mvn/maven-wrapper.properties
-  Maven mvn = new MavenWrapper(this)
+  Maven mvn = new MavenWrapperInDocker(this)
 
   if (isMainBranch()) {
     // Release starts javadoc, which takes very long, so do only for certain branches

build/Dockerfile

@@ -0,0 +1,4 @@
+FROM adoptopenjdk/openjdk11:x86_64-debian-jdk-11.0.6_10
+
+# install mercurial, which is required for integration tests
+RUN apt-get update && apt-get install -y mercurial

build/Makefile

@@ -0,0 +1,9 @@
+VERSION:=11.0.6_10
+
+.PHONY:build
+build:
+	docker build -t scmmanager/java-build:${VERSION} .
+
+.PHONY:publish
+publish: build
+	docker push scmmanager/java-build:${VERSION}

build/README.md

@@ -0,0 +1,3 @@
+# Build tools
+
+This folder contains tools required to build scm-manager