Add .gitattributes to prevent overwriting of the Readme file

when merging hotfix branches to develop

From: http://www.alberts.me/post/always-keep-your-copy-of-a-particular-file-in-a-git-merge/

git config merge.ours.name '"always keep ours" merge driver'
git config merge.ours.driver 'touch %A'
echo "README.rst merge=ours" >> .gitattributes
git add .gitattributes
git commit -m "keep my copy of the README.rst file"

Author: iMichka

.gitattributes

@@ -0,0 +1 @@
+README.rst merge=ours