objectracker.py should be renamed to objecttracker.py #2232

objectracker.py should be renamed to objecttracker.py .
Duplicated TT is mandatory.

Although, there seems no naming conventions in this project.
It should be some, but may be difficult to introduce anyway.

My name is Kashiko Koibumi, and for ID kashikokoibumi is too long, so I squashed it to kashikoibumi.
It's the same strategy, but don't use in coding.