Remove CONTRIBUTING.
Remove CONTRIBUTING.

bjaglin/crane,michaelsauter/crane,jesper/crane,jesper/crane,inthroxify/crane,bjaglin/crane,tmc/crane,dreamcat4/crane,stajkowski/crane,dreamcat4/crane,rmoorman/crane,t-suwa/crane,inthroxify/crane,tmc/crane,michaelsauter/crane,rmoorman/crane,t-suwa/crane,stajkowski/crane