Trailing LF character is added when content files are zipped

[nabeta]

I noticed willow_sword adds a trailing LF character to content files when it creates a zip file. The following is an example to create a zip file for public directory in a Rails project.

$ rails c
> file = WillowSword::ZipPackage.new('public', 'data/test.zip')
> file.create_zip

$ unzip test.zip -d tmp
$ diff -u tmp/apple-touch-icon.png hyrax/public/apple-touch-icon.png
Binary files tmp/apple-touch-icon.png and hyrax/public/apple-touch-icon.png differ
$ cmp tmp/apple-touch-icon.png hyrax/public/apple-touch-icon.png
cmp: EOF on hyrax/public/apple-touch-icon.png after byte 5401, in line 26