Add basic harness for testing running boot apps

Used mockito to mock list of running apps.

headless-services/boot-java-language-server/pom.xml

@@ -67,6 +67,12 @@
 			<artifactId>commons-boot-app-cli</artifactId>
 			<version>${dependencies.version}</version>
 		</dependency>
+		<dependency>
+			<groupId>org.mockito</groupId>
+			<artifactId>mockito-all</artifactId>
+			<version>${mockito-version}</version>
+			<scope>test</scope>
+		</dependency>
 
 		<!-- Eclipse JDT for parsing (at the moment) -->
 		<dependency>