Remove some of my battle contributions

It seems a recent backup restore may have selectively reverted my robocode roborumble config file, dramatically decreasing the cpu constant I use in my rumble configuration. Since I run many concurrently this `could have had` considerable negative rating for some robots.

So I ask you remove my contribs from the 15th onward. I apologize for not noticing this sooner.

No worries, I have a mostly-automated method for cleanup. Will do this in the next few days as soon as I get some free time. Everything from the 15th to the 20th (inclusive)?