[jsk_fetch_startup] add time_signal.py

[knorth55]

I don't know who, but someone left this script in fetch15 home directory.
so I move this script into jsk_robot.
this node is added in crontab as below.

0 * * * * /home/fetch/ros/indigo/devel/env.sh rosrun jsk_fetch_startup time_signal.py

cc. @708yamaguchi @iory

[708yamaguchi]

I am sorry, but I left this script to fetch's home directory. In my memory, this script works correctly.

However, some people say, "I feel like being rushed when fetch speaks time signal."
Then, I have no idea whether this script should be used...

[knorth55]

lets save this script in jsk_robot first.
then think about how to use this later.

[knorth55]

we run this script for a week and no one claims about it.