tagmanifest checksums calculated on Windows are incorrect

[aelkiss]

Checksums for manifest files are calculated incorrectly because the file is read with line-ending conversion. To fix this, just use File.open(f,"rb") instead of the default File.open(f) where mode defaults to r

bagit/lib/bagit/manifest.rb

Line 135 in 9199fdc

data = File.open(f, &:read)