Update versions, refactor, cleanup.

.drone.yml

@@ -1,12 +1,20 @@
 kind: pipeline
 type: docker
 name: default
-
 steps:
-  - name: test
-    image: maven:3.6-jdk-11
+  - name: build
+    image: maven:3.8-openjdk-18-slim
     commands:
       - mvn clean install -DskipTests=true -Dmaven.javadoc.skip=true -B -V
+    when:
+      ref:
+        include:
+          - refs/head/master
+          - refs/head/feature/**
+          - refs/tags/**
+  - name: test
+    image: maven:3.8-openjdk-18-slim
+    commands:
       - mvn test -B
     when:
       branch:
@@ -14,15 +22,15 @@ steps:
           - master
           - feature/*
   - name: deploy
-    image: maven:3.6-jdk-11
+    image: maven:3.8-openjdk-18-slim
     environment:
       REPO_TOKEN:
         from_secret: repo-token
     commands:
       - mvn -s maven-settings.xml deploy -DskipTests=true
-    trigger:
+    when:
       branch:
         - master
       event:
         exclude:
-        - pull_request
+          - pull_request