eol=lf for .gitattributes (#2484)

hopefully fixes CRLF-LF issues for windows users.
see https://git-scm.com/docs/gitattributes#Documentation/gitattributes.txt-Settostringvaluelf

.gitattributes

@@ -1,6 +1,6 @@
 # Automatically normalize line endings for all files
 # detected as text (Convert CRLF => LF).
-*         text=auto
+*         text=auto eol=lf
 
 # Explicitly normalize files with these extensions in
 # case Git doesn't detect them as text for some reason.