Fix a problem regarding EOL on macOS (#202)

Here's more information: https://help.github.com/articles/dealing-with-line-endings/

After cloning this repository if someone does not set `core.autocrlf` properly may encounter a problem with EOL.

.gitattributes

@@ -1 +1,6 @@
-* text eol=lf
+* text eol=lf
+
+*.png binary
+*.jpg binary
+*.ico binary
+*.woff2 binary