Merge branch 'develop' into jdk-9-compatible

* develop:
  Add missing error when snapshot
  version set to 0.6.0-SNAPSHOT (again)
  jenkins: use mvn with options
  jenkins: clean up
  jenkins: fix syntax #5
  jenkins: fix syntax #4
  jenkins: fix syntax #3
  jenkins: strong type read pom
  jenkins: fix syntax #2
  jenkins: fix syntax #2
  jenkins: fix syntax
  jenkins: fix syntax
  Revert "version set to 0.6.0-SNAPSHOT"
  jenkins: add check to fail build when SNAPSHOT on master branch
  version set to 0.6.0-SNAPSHOT
  pom: fix accidental merge of SNAPSHOT into master
  version: set to 0.6.0-SNAPSHOT
  version: set to 0.5.0

CHANGELOG

@@ -1,6 +1,11 @@
 CHANGELOG
 =========
 
+0.5.1
+-----
+
+* Fix accidental merge with SNAPSHOT version in to master
+
 0.5.0
 -----
 
@@ -9,7 +14,6 @@ CHANGELOG
 * Add `BeanBuilder` experiment
 * Upgrade `lombok` to 1.16.20
 * Upgrade assertj to 3.9.1
-* jenkins: test on both java 8 and 9
 
 0.4.0
 -----

Jenkinsfile.groovy

@@ -9,12 +9,24 @@ pipeline {
                 git url: gitRepoUrl, branch: '**', credentialsId: 'github-kemitix'
             }
         }
+        stage('no SNAPSHOT in master') {
+            // checks that the pom version is not a snapshot when the current branch is master
+            // TODO: also check for SNAPSHOT when is a pull request with master as the target branch
+            when {
+                expression {
+                    (env.GIT_BRANCH == 'master') &&
+                            (readMavenPom(file: 'pom.xml').version).contains("SNAPSHOT") }
+            }
+            steps {
+                error("Build failed because SNAPSHOT version")
+            }
+        }
         stage('Build') {
             parallel {
                 stage('Java 8') {
                     steps {
                         withMaven(maven: 'maven 3.5.2', jdk: 'JDK 1.8') {
-                            sh 'mvn clean install'
+                            sh "${mvn} clean install"
                         }
                     }
                 }

pom.xml

@@ -12,7 +12,7 @@
     </parent>
     <groupId>net.kemitix</groupId>
     <artifactId>mon</artifactId>
-    <version>0.5.0-SNAPSHOT</version>
+    <version>0.6.0-SNAPSHOT</version>
 
     <properties>
         <java.version>1.8</java.version>