[jsk_network_tools] Disable test

[garaemon]

/opt/ros/indigo/share/rostest/cmake/../../../bin/rostest --pkgdir=/workspace/ros/ws_jsk_common/src/jsk_common/jsk_network_tools --package=jsk_network_tools --results-filename test_test_all_type_low_speed.xml --results-base-dir /workspace/ros/ws_jsk_common/build/jsk_network_tools/test_results /workspace/ros/ws_jsk_common/src/jsk_common/jsk_network_tools/test/test_all_type_low_speed.test 
... logging to /workspace/jsk-ros-pkg/jsk_common/log/rostest-e92918266336-8154.log
[ROSUNIT] Outputting test results to /workspace/ros/ws_jsk_common/build/jsk_network_tools/test_results/jsk_network_tools/rostest-test_test_all_type_low_speed.xml
testtest_all_type_low_speed ... FAILURE!
FAILURE: Package [jsk_network_tools] for test node [jsk_network_tools/test_all_type_low_speed.py] does not exist
  File "/usr/lib/python2.7/unittest/case.py", line 331, in run
    testMethod()
  File "/opt/ros/indigo/lib/python2.7/dist-packages/rostest/runner.py", line 93, in fn
    self.fail(message)
  File "/usr/lib/python2.7/unittest/case.py", line 412, in fail
    raise self.failureException(msg)