Test Regression from #35

[azeey]

The following tests have started failing since #35

• DepthCameraSensor/DepthCameraSensorTest.ImagesWithBuiltinSDF/ogre2

/var/lib/jenkins/workspace/ignition_sensors-ci-ign-sensors2-bionic-amd64/ign-sensors/test/integration/depth_camera_plugin.cc:435
The difference between expectedDepth and d is 0.19999999999999996, which exceeds 1e-6, where
expectedDepth evaluates to 0.19999999999999996,
d evaluates to 0, and
1e-6 evaluates to 9.9999999999999995e-07.

• RgbdCameraSensor/RgbdCameraSensorTest.ImagesWithBuiltinSDF/ogre2

/var/lib/jenkins/workspace/ignition_sensors-ci-ign-sensors2-bionic-amd64/ign-sensors/test/integration/rgbd_camera_plugin.cc:553
Expected equality of these values:
  -ignition::math::INF_D
    Which is: -inf
  g_depthBuffer[index]
    Which is: 0

[chapulina]

Probably caused by gazebosim/gz-rendering#129

[iche033]

being addressed in gazebosim/gz-rendering#130