update .gitmodules

.gitmodules

 [submodule "src/franka_description"]
 	path = src/franka_description
-	url = ../franka_description.git
+	url = ../../franka_description.git
 [submodule "src/panda_moveit_config"]
 	path = src/panda_moveit_config
-	url = ../panda_moveit_config.git
+	url = ../../panda_moveit_config.git
 [submodule "src/panda_simulation"]
 	path = src/panda_simulation
-	url = ../panda_simulation.git
+	url = ../../panda_simulation.git
 [submodule "src/sample_applications"]
 	path = src/sample_applications
 	url = ../sample_applications.git
 [submodule "src/panda_teaching"]
 	path = src/panda_teaching
-	url = ../panda_teaching.git
+	url = ../../panda_teaching.git
 [submodule "src/simulation_util"]
 	path = src/simulation_util
-	url = ../simulation_util.git
+	url = ../../simulation_util.git
 	branch = master
 [submodule "src/gazebo-pkgs"]
 	path = src/gazebo-pkgs
@@ -25,7 +25,7 @@
 	url = https://github.com/JenniferBuehler/general-message-pkgs.git
 [submodule "src/tutorial_ros_hello_world"]
 	path = src/tutorial_ros_hello_world
-	url = ../ceti-summer-school/tutorial_ros_hello_world.git
+	url = ../../ceti-summer-school/tutorial_ros_hello_world.git
 [submodule "src/tutorial_ros_pub_sub"]
 	path = src/tutorial_ros_pub_sub
-	url = ../ceti-summer-school/tutorial_ros_pub_sub.git
+	url = ../../ceti-summer-school/tutorial_ros_pub_sub.git