Force a GC run.
Force a GC run.

Some of the reference tests fail otherwise because some file handles
are kept open and windows can't delete folders with opened files in them.

libgit2/rugged,saraid/rugged,tpickett66/rugged,Acidburn0zzz/rugged,saraid/rugged,tpickett66/rugged,saraid/rugged,libgit2/rugged,tpickett66/rugged,libgit2/rugged,Acidburn0zzz/rugged,Acidburn0zzz/rugged