Keybase PGP on Mac cannot handle line endings from Enigmail

When Enigmail encrypts a message within Thunderbird it creates a ASCII Armored PGP message with just 0x0D to separate lines.

When run through: `keybase pgp decrypt -i X.asc -o X`, keybase terminates with `ERROR EOF`

Would be useful to be able to handle files with just 0x0D as line separators.

Start at the `keybase pgp decrypt -i X.asc -o X` entry point and reproduce the failure using an ASCII-armored Enigmail message whose lines are separated by 0x0D. Done means the command decrypts files using CR-only line separators without returning `ERROR EOF`.

Written by the indexing model from the issue text.