[maven-release-plugin] prepare release RoaringBitmap-0.6.51
[maven-release-plugin] prepare release RoaringBitmap-0.6.51

lemire/RoaringBitmap,RoaringBitmap/RoaringBitmap,lemire/RoaringBitmap,lemire/RoaringBitmap,RoaringBitmap/RoaringBitmap,lemire/RoaringBitmap,RoaringBitmap/RoaringBitmap,RoaringBitmap/RoaringBitmap