simplify version management

Author: tobiasstadler

pom.xml

@@ -26,24 +26,27 @@
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
         <maven.compiler.source>1.8</maven.compiler.source>
         <maven.compiler.target>1.8</maven.compiler.target>
+        <apache.activemq.version>2.44.0</apache.activemq.version>
+        <elastic.apm.agent.version>1.55.2</elastic.apm.agent.version>
+        <mockserver.version>5.15.0</mockserver.version>
     </properties>
 
     <dependencyManagement>
         <dependencies>
             <dependency>
                 <groupId>co.elastic.apm</groupId>
                 <artifactId>apm-agent-api</artifactId>
-                <version>1.55.2</version>
+                <version>${elastic.apm.agent.version}</version>
             </dependency>
             <dependency>
                 <groupId>co.elastic.apm</groupId>
                 <artifactId>apm-agent-attach</artifactId>
-                <version>1.55.2</version>
+                <version>${elastic.apm.agent.version}</version>
             </dependency>
             <dependency>
                 <groupId>co.elastic.apm</groupId>
                 <artifactId>apm-agent-plugin-sdk</artifactId>
-                <version>1.55.2</version>
+                <version>${elastic.apm.agent.version}</version>
             </dependency>
             <dependency>
                 <groupId>com.jayway.jsonpath</groupId>
@@ -53,17 +56,17 @@
             <dependency>
                 <groupId>org.apache.activemq</groupId>
                 <artifactId>artemis-core-client</artifactId>
-                <version>2.44.0</version>
+                <version>${apache.activemq.version}</version>
             </dependency>
             <dependency>
                 <groupId>org.apache.activemq</groupId>
                 <artifactId>artemis-jms-client</artifactId>
-                <version>2.44.0</version>
+                <version>${apache.activemq.version}</version>
             </dependency>
             <dependency>
                 <groupId>org.apache.activemq</groupId>
                 <artifactId>artemis-server</artifactId>
-                <version>2.44.0</version>
+                <version>${apache.activemq.version}</version>
             </dependency>
             <dependency>
                 <groupId>org.junit.jupiter</groupId>
@@ -73,12 +76,12 @@
             <dependency>
                 <groupId>org.mock-server</groupId>
                 <artifactId>mockserver-client-java</artifactId>
-                <version>5.15.0</version>
+                <version>${mockserver.version}</version>
             </dependency>
             <dependency>
                 <groupId>org.mock-server</groupId>
                 <artifactId>mockserver-junit-jupiter</artifactId>
-                <version>5.15.0</version>
+                <version>${mockserver.version}</version>
             </dependency>
             <dependency>
                 <groupId>org.slf4j</groupId>