add gitattributes
other possible solutions (taken from hanselman's blog)
+ Git needs to install with correct platform-specific defaults without needing .gitattributes file
+ Have the GitHub web application be more proactive in suggesting solutions and preventing badness
+ Have the GitHub for Windows desktop application proactively notice issues (before I go to settings) and offer to help
+ Make the diff tool CR/LF aware and "do the right thing" like desktop diff tools that can ignore line ending issues
+ Until something is done, I'll always tense up when I see an incoming pull request and hope it's not a Wall of Pink.