[ROS 2] projection_test timing out on macOS

[jacobperron]

For the last couple days, the test has been timing out on macOS nightly CI:

• https://ci.ros2.org/view/nightly/job/nightly_osx_repeated/2019/testReport/junit/(root)/laser_geometry/projection_test_gtest_missing_result/
• https://ci.ros2.org/view/nightly/job/nightly_osx_repeated/2018/testReport/junit/(root)/laser_geometry/projection_test_gtest_missing_result/

Example output:

06:31:12 5: [==========] Running 1 test from 1 test case.
06:31:12 5: [----------] Global test environment set-up.
06:31:12 5: [----------] 1 test from laser_geometry
06:31:12 5: [ RUN      ] laser_geometry.projectLaser2
06:34:12     Test #5: projection_test ..................***Timeout 180.13 sec

I haven't seen similar failures for other platforms.

[dirk-thomas]

Fixed by #63.