Add unit test for "\n" instead of "\r\n" in RFC5322 parsing.
Add unit test for "\n" instead of "\r\n" in RFC5322 parsing.

This (and the commit cherry picked before it) fixes #11

niax/rust-email,untitaker/rust-email,buster/rust-email,niax/rust-email,buster/rust-email,hoodie/rust-email,hoodie/rust-email