Always write files in binary mode when unzipping

Prevents CRLF conversion on Windows, which was corrupting SKP files
downloaded with fetch-skps

BUG=skia:

GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=4210

Change-Id: Ia876f403d10792ee185d50a29fe30402b733441d
Reviewed-on: https://skia-review.googlesource.com/4210
Reviewed-by: Robert Phillips <robertphillips@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
1 file changed