Fix build issues and update to sling 47 (#1)

diff --git a/README.md b/README.md
index 415d20b..70e816e 100644
--- a/README.md
+++ b/README.md
@@ -1,6 +1,6 @@
 [![Apache Sling](https://sling.apache.org/res/logos/sling.png)](https://sling.apache.org)
 
- [![Build Status](https://ci-builds.apache.org/job/Sling/job/modules/job/sling-org-apache-sling-commons-cache-impl/job/master/badge/icon)](https://ci-builds.apache.org/job/Sling/job/modules/job/sling-org-apache-sling-commons-cache-impl/job/master/) [![Coverage](https://sonarcloud.io/api/project_badges/measure?project=apache_sling-org-apache-sling-commons-cache-impl&metric=coverage)](https://sonarcloud.io/dashboard?id=apache_sling-org-apache-sling-commons-cache-impl) [![Sonarcloud Status](https://sonarcloud.io/api/project_badges/measure?project=apache_sling-org-apache-sling-commons-cache-impl&metric=alert_status)](https://sonarcloud.io/dashboard?id=apache_sling-org-apache-sling-commons-cache-impl) [![Contrib](https://sling.apache.org/badges/status-contrib.svg)](https://github.com/apache/sling-aggregator/blob/master/docs/status/contrib.md) [![License](https://img.shields.io/badge/License-Apache%202.0-blue.svg)](https://www.apache.org/licenses/LICENSE-2.0)
+ [![Build Status](https://ci-builds.apache.org/job/Sling/job/modules/job/sling-org-apache-sling-commons-cache-impl/job/master/badge/icon)](https://ci-builds.apache.org/job/Sling/job/modules/job/sling-org-apache-sling-commons-cache-impl/job/master/) [![Test Status](https://img.shields.io/jenkins/tests.svg?jobUrl=https://ci-builds.apache.org/job/Sling/job/modules/job/sling-org-apache-sling-commons-cache-impl/job/master/)](https://ci-builds.apache.org/job/Sling/job/modules/job/sling-org-apache-sling-commons-cache-impl/job/master/test/?width=800&height=600) [![Coverage](https://sonarcloud.io/api/project_badges/measure?project=apache_sling-org-apache-sling-commons-cache-impl&metric=coverage)](https://sonarcloud.io/dashboard?id=apache_sling-org-apache-sling-commons-cache-impl) [![Sonarcloud Status](https://sonarcloud.io/api/project_badges/measure?project=apache_sling-org-apache-sling-commons-cache-impl&metric=alert_status)](https://sonarcloud.io/dashboard?id=apache_sling-org-apache-sling-commons-cache-impl) [![JavaDoc](https://www.javadoc.io/badge/org.apache.sling/org.apache.sling.api.svg)](https://www.javadoc.io/doc/org.apache.sling/org.apache.sling.api) [![Maven Central](https://maven-badges.herokuapp.com/maven-central/org.apache.sling/org.apache.sling.api/badge.svg)](https://search.maven.org/#search%7Cga%7C1%7Cg%3A%22org.apache.sling%22%20a%3A%22org.apache.sling.api%22) [![License](https://img.shields.io/badge/License-Apache%202.0-blue.svg)](https://www.apache.org/licenses/LICENSE-2.0)
 
 # Apache Sling Cache API Implementation support library
 
diff --git a/pom.xml b/pom.xml
index 701e84f..4bc9ca5 100644
--- a/pom.xml
+++ b/pom.xml
@@ -23,8 +23,8 @@
     <parent>
         <groupId>org.apache.sling</groupId>
         <artifactId>sling</artifactId>
-        <version>16</version>
-        <relativePath/>
+        <version>47</version>
+        <relativePath />
     </parent>
 
     <artifactId>org.apache.sling.commons.cache.impl</artifactId>
@@ -36,12 +36,17 @@
         This bundle provides an implementation support for Cache implementations. It is a utility jar that should be embedded.
     </description>
 
+    <properties>
+        <sling.java.version>8</sling.java.version>
+        <project.build.outputTimestamp>1</project.build.outputTimestamp>
+    </properties>
+
     <scm>
         <connection>scm:git:https://gitbox.apache.org/repos/asf/sling-org-apache-sling-commons-cache-impl.git</connection>
         <developerConnection>scm:git:https://gitbox.apache.org/repos/asf/sling-org-apache-sling-commons-cache-impl.git</developerConnection>
         <url>https://gitbox.apache.org/repos/asf?p=sling-org-apache-sling-commons-cache-impl.git</url>
+        <tag>HEAD</tag>
     </scm>
-    
 
     <dependencies>
         <dependency>