ROS IDL tutorial build problem

[AndyBlightLeeds]

I was working through the tutorial https://index.ros.org/doc/ros2/Tutorials/Rosidl-Tutorial/. When I tried to build the code with no changes, I received the error message:

$ git checkout rosidl_tutorials 
Switched to branch 'rosidl_tutorials'
Your branch is up-to-date with 'origin/rosidl_tutorials'.
$ cd ../..
$ colcon build --packages-select rosidl_tutorials_msgs
Starting >>> rosidl_tutorials_msgs
--- stderr: rosidl_tutorials_msgs                         
CMake Error at /opt/ros/eloquent/share/rosidl_cmake/cmake/rosidl_generate_interfaces.cmake:229 (message):
  Packages installing interfaces must include
  '<member_of_group>rosidl_interface_packages</member_of_group>' in their
  package.xml
Call Stack (most recent call first):
  CMakeLists.txt:24 (rosidl_generate_interfaces)

make: *** [cmake_check_build_system] Error 1
---
Failed   <<< rosidl_tutorials_msgs      [ Exited with code 2 ]

Summary: 0 packages finished [0.75s]
  1 package failed: rosidl_tutorials_msgs
  1 package had stderr output: rosidl_tutorials_msgs

This error was also noted on issue #1.

I have fixed this problem and will submit a pull request.

[AndyBlightLeeds]

Fix is on #27, so this can be closed.

[AndyBlightLeeds]

Forgot to mention, using ROS2 eloquent.