Signing and use nexus-staging plugin

Author: tschuchortdev

build.gradle

@@ -19,6 +19,10 @@ plugins {
     id 'io.codearte.nexus-staging' version '0.22.0' //can only be applied to root project
 }
 
+nexusStaging {
+    username = "$System.env.SONATYPE_NEXUS_USERNAME"
+    password = "$System.env.SONATYPE_NEXUS_PASSWORD"
+}
 
 allprojects {
     group 'com.github.tschuchortdev'
@@ -47,6 +51,7 @@ allprojects {
     apply plugin: 'kotlin'
     apply plugin: 'java'
     apply plugin: 'idea'
+    apply plugin: 'signing'
     apply plugin: 'maven-publish'
 
     if (JavaVersion.current().isJava8Compatible()) {
@@ -68,6 +73,7 @@ subprojects {
         archiveClassifier = 'javadoc'
         from javadoc.destinationDir
     }
+
     publishing {
         publications {
             mavenJava(MavenPublication) {
@@ -117,6 +123,10 @@ subprojects {
         }
     }
 
+    signing {
+        sign publishing.publications.mavenJava
+    }
+
     dependencies {
         implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk8"