Added missing maven-publish plugin.

Signed-off-by: Johannes Tegnér <johannes@jitesoft.com>

Author: Johannestegner

build.gradle

@@ -1,4 +1,5 @@
 plugins {
+    id 'maven-publish'
     id 'java'
     id 'java-library'
 }
@@ -17,6 +18,13 @@ dependencies {
     implementation 'dev.personnummer:personnummer:3.3.3'
 }
 
+jar {
+    manifest {
+        attributes('Implementation-Title': project.name,
+                'Implementation-Version': project.version)
+    }
+}
+
 java {
     withJavadocJar()
     withSourcesJar()