make use of non-gpu laser by default update min/max range to fix ghost objects (#27)

Author: fjp

diffbot_description/urdf/diffbot.urdf.xacro

@@ -63,7 +63,8 @@
 
   <!-- Sensors -->
   <xacro:laser prefix="rplidar" parent_link="base_link"
-                   sensor_prop="${sensor_prop}"> 
+                   sensor_prop="${sensor_prop}"
+                   enable_gpu="${sensor_prop['laser']['enable_gpu']}">
   </xacro:laser>
 
   <!-- Gazebo -->

diffbot_description/urdf/include/common_sensors.xacro

@@ -75,8 +75,8 @@
           </horizontal>
         </scan>
         <range>
-          <min>0.10</min>
-          <max>30.0</max>
+          <min>0.12</min>
+          <max>12.0</max>
           <resolution>0.01</resolution>
         </range>
         <noise>