Use mock_components instead of fake_components (UniversalRobots#37)

This has been renamed in ros2_control hardware_interface.

Author: Abishalini

urdf/ur.ros2_control.xacro

@@ -27,7 +27,7 @@
           <plugin>ign_ros2_control/IgnitionSystem</plugin>
         </xacro:if>
         <xacro:if value="${use_fake_hardware}">
-          <plugin>fake_components/GenericSystem</plugin>
+          <plugin>mock_components/GenericSystem</plugin>
           <param name="fake_sensor_commands">${fake_sensor_commands}</param>
           <param name="state_following_offset">0.0</param>
         </xacro:if>