Baxter simulator for ros testing - gazebo aborts [1]

[alecive]

Hello,

I am trying to set up travis builds with an headless gazebo server to perform ros tests and integration tests. I am having a number of problems, which I will place in independent issues for the sake of sanity.

Problem 1 is that sometimes gazebo crashes with the following error:

[ INFO][/baxter_emulator::service::exists]: waitForService: Service [/gazebo/get_link_properties] has not been advertised, waiting...
X Error of failed request:  BadDrawable (invalid Pixmap or Window parameter)
  Major opcode of failed request:  154 (DRI2)
  Minor opcode of failed request:  3 (DRI2CreateDrawable)
  Resource id in failed request:  0x4a00002
  Serial number of failed request:  31
  Current serial number in output stream:  33
[INFO][/robot/controller_spawner::main]: Controller Spawner: Waiting for service controller_manager/load_controller
[INFO][/robot/controller_spawner_stopped::main]: Controller Spawner: Waiting for service controller_manager/load_controller
[INFO][/robot/left_gripper_controller_spawner_stopped::main]: Controller Spawner: Waiting for service controller_manager/load_controller
[INFO][/robot/right_gripper_controller_spawner_stopped::main]: Controller Spawner: Waiting for service controller_manager/load_controller
gzserver: /usr/include/boost/thread/pthread/recursive_mutex.hpp:101: boost::recursive_mutex::~recursive_mutex(): Assertion `!pthread_mutex_destroy(&m)' failed.
Aborted (core dumped)

this happens only if I launch baxter_world.launch from a rostest, not from a roslaunch.

See #115 and #116 as well.