added dependencies and description

Author: bharadwaj-chukkala

package.xml

@@ -3,14 +3,19 @@
 <package format="3">
   <name>beginner_tutorials</name>
   <version>0.0.0</version>
-  <description>Examples of minimal publisher/subscriber using rclcpp</description>
+  <description>Implementation of tf2, unit testing and ros bag</description>
   <maintainer email="bchukkal@terpmail.umd.edu">bharadwaj</maintainer>
   <license>Apache License 2.0</license>
 
   <buildtool_depend>ament_cmake</buildtool_depend>
   <depend>rclcpp</depend>
   <depend>std_msgs</depend>
-  <depend>example_interfaces</depend>
+  <depend>tf2</depend>
+  <depend>tf2_ros</depend>
+  <build_depend>rosidl_default_generators</build_depend>
+  <exec_depend>rosidl_default_runtime</exec_depend>
+  <exec_depend>ros2launch</exec_depend>
+  <member_of_group>rosidl_interface_packages</member_of_group>
 
   <test_depend>ament_lint_auto</test_depend>
   <test_depend>ament_lint_common</test_depend>