Added an example launch file and the configuration file for the RP-LIDAR A2 in simulation.

config/rplidar_a2.yaml

+pose_x: 0
+pose_y: 0
+pose_z: 0
+pose_roll: 0
+pose_pitch: 0
+pose_yaw: 0
+visualize: false
+update_rate: 10
+samples: 400
+resolution: 1
+min_angle: -3.14159
+max_angle: 3.14159
+range_min: 0.15
+range_max: 6.0
+range_resolution: 0.05
+noise_type: 'gaussian'
+noise_mean: 0.0
+noise_stddev: 0.01
+topic_name: 'scan'
+#frame_name: 'scan_frame'

launch/hokuyo_laser2d_sim.launch

@@ -34,4 +34,4 @@
         args="-d $(find iri_laser2d_gazebo)/rviz/laser.rviz">
   </node>
 
-</launch>
\ No newline at end of file
+</launch>

launch/rplidar_laser2d_sim.launch

+<?xml version="1.0" encoding="UTF-8"?>
+<launch>
+
+  <!-- We resume the logic in empty_world.launch, changing only the name of the world to be launched -->
+  <include file="$(find gazebo_ros)/launch/empty_world.launch">
+    <arg name="paused" value="false"/>
+    <arg name="use_sim_time" value="true"/>
+    <arg name="extra_gazebo_args" value=""/>
+    <arg name="gui" value="true"/>
+    <arg name="recording" value="false"/>
+    <arg name="headless" value="false"/>
+    <arg name="debug" value="false"/>
+    <arg name="physics" value="ode"/>
+    <arg name="verbose" value="false"/>
+    <arg name="world_name" value="worlds/empty.world"/> 
+    <arg name="respawn_gazebo" value="false"/>
+    <arg name="use_clock_frequency" value="false"/>
+    <arg name="pub_clock_frequency" value="100"/>
+  </include>
+
+  <param name="robot_description"
+         command="$(find xacro)/xacro --inorder '$(find iri_rplidar_laser2d_description)/urdf/rplidar_laser2d_example.xacro'" />
+
+  <node pkg="robot_state_publisher" type="state_publisher" name="rplidar_tf_broadcaster">
+    <param name="tf_prefix" type="string" value="/"/>
+    <param name="publish_frequency" type="double" value="20.0"/>
+  </node>
+
+  <node name="spawn_urdf" pkg="gazebo_ros" type="spawn_model" args="-param robot_description -urdf -model rplidar_laser2d -x 0 -y 0 -z 0 -R 0 -P 0 -Y 0" />
+  
+  <node name="rviz"
+        pkg="rviz"
+        type="rviz"
+        args="-d $(find iri_laser2d_gazebo)/rviz/laser.rviz">
+  </node>
+
+</launch>