Add gt_logger launch file for testing

Author: marcusabate

launch/gt_logger.launch

@@ -0,0 +1,10 @@
+<launch>
+  <arg name="gt_topic" default="/tesse/odom"/>
+  <arg name="output_dir" default="$(find spark_vio_ros)/output_logs/TESSE/"/>
+
+  <node name="gt_logger_node" pkg="spark_vio_ros" type="gt_logger_node.py"
+        output="screen">
+    <param name="gt_topic"   value="$(arg gt_topic)"/>
+    <param name="output_dir" value="$(arg output_dir)"/>
+  </node>
+</launch>