Set minimal Java version for vendor EJB plug-ins

Author: arjantijms

ejb/remote/vendor/pom.xml

@@ -11,9 +11,24 @@
 
     <properties>
     	<glassfish.client.version>5.0</glassfish.client.version>
+        <java.min.version>1.7</java.min.version>
     </properties>
 
     <name>Java EE 7 Sample: ejb - remote - vendor</name>
+    
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-compiler-plugin</artifactId>
+                <version>3.8.0</version>
+                <configuration>
+                    <source>${java.min.version}</source>
+                    <target>${java.min.version}</target>
+                </configuration>
+            </plugin>
+        </plugins>
+    </build>
 
     <profiles>
         <profile>