Add water and sky textures to underwater Gazebo world (#299)

* Consolidated worlds into a single file

* Added water and sky textures to underwater world

* what

* Remove random change

(cherry picked from commit 5b34879)

blue_description/gazebo/worlds/bluerov2_underwater.world

@@ -43,5 +43,26 @@
  <pose>0 7 -10 0 0 0</pose>
  </include>
 
+ <include>
+ <uri>
+ https://fuel.gazebosim.org/1.0/OpenRobotics/models/Coast Water
+ </uri>
+ <pose>0 0 0 0 0 0</pose>
+ </include>
+
+ <scene>
+ <ambient>1.0 1.0 1.0</ambient>
+ <background>0.8 0.8 0.8</background>
+ <sky></sky>
+ </scene>
+
+ <light type="directional" name="sun1">
+ <pose>50 0 150 0 0 0</pose>
+ <diffuse>1 1 1 1</diffuse>
+ <specular>.1 .1 .1 1</specular>
+ <direction>0.3 0.3 -1</direction>
+ <cast_shadows>false</cast_shadows>
+ </light>
+
  </world>
 </sdf>