Log Message:
Update ruby-zip to 1.1.6.

1.1.6

    Revert "Return created zip file from Zip::File.open when supplied a \ 
block"

1.1.5

    Treat empty file as non-exists (@layerssss)
    Revert regression commit
    Return created zip file from Zip::File.open when supplied a block (@tpickett66)
    Zip::Entry::DEFLATED is forced on every file (@mehmetc)
    Add InputStream#ungetc (@zacstewart)
    Alias for legacy error names (@orien)