Update .gitattributes
Squashed 'src/snappy/snappy/' content from commit 1ff9be9

git-subtree-dir: src/snappy/snappy
git-subtree-split: 1ff9be9b8fafc8528ca9e055646f5932aa5db9c4
Merge commit 'b24a2b9c52db2bd93430c248fb8943738158b08d' as 'src/snappy/snappy'