Update Jenkinsfile & Create Dockerfile

Experiment with Dockerfile to allow deployment to ossrh

Dockerfile

@@ -0,0 +1,6 @@
+FROM maven:3.8.1-adoptopenjdk-11
+
+COPY settings.xml /root/.m2
+
+RUN apt-get update && sudo apt-get upgrade && sudo apt-get dist-upgrade
+RUN apt install gpg

Jenkinsfile

@@ -1,7 +1,6 @@
 pipeline {
     agent {
-        docker {
-            image "maven:3.8.1-adoptopenjdk-11"
+        dockerfile {
             args '-v /root/.m2:/root/.m2'
         }
     }