Add props to the pool world (#100)

* Add texture models (gate and torpedo)

* Change prop locations

auv_sim/auv_sim_description/auv_sim_description/models/robosub_bin/model.config

@@ -0,0 +1,15 @@
+<?xml version="1.0"?>
+<model>
+    <name>robosub_bin</name>
+    <version>1.0</version>
+    <sdf version='1.6'>model.sdf</sdf>
+
+    <author>
+        <name>Levent Emre Nalici</name>
+        <email>nalicilevent@gmail.com</email>
+    </author>
+
+    <description>
+        robosub bin
+    </description>
+</model>

auv_sim/auv_sim_description/auv_sim_description/models/robosub_bin/model.sdf

@@ -0,0 +1,27 @@
+<?xml version="1.0"?>
+<sdf version="1.6">
+	<model name="robosub_bin">
+		<static>true</static>
+    	<pose>0 0 0 0 0 0</pose>
+		<link name="robosub_bin">
+			<pose>0 0 0 0 0 0</pose>
+			<collision name="robosub_bin_col">
+				<pose>0 0 0 0 0 0</pose>
+				<geometry>
+					<mesh>
+						<uri>model://robosub_bin/meshes/bin.dae</uri>
+					</mesh>
+				</geometry>
+			</collision>
+			<visual name="robosub_bin_vis">
+				<pose>0 0 0 0 0 0</pose>
+				<geometry>
+					<mesh>
+						<uri>model://robosub_bin/meshes/bin.dae</uri>
+					</mesh>
+				</geometry>
+			</visual>
+
+		</link>
+	</model>
+</sdf>