Added a decodeSection function to mime.go that uses go-qprintable to
parse quoted-printable emails or MIME parts, fixes#7
Added a very basic TextToHtml converter to provide nicer rending of text
message bodies.
MIME parsing code is now in an acceptable state to integrate into
web UI. It should be able to display text and/or HTML (sans
attachments).
Added "testify" unit testing library, providing assertions and mocks.
I'm hoping to mostly rely on the official mime and mime/multipart
packages, but Inbucket is still going to have to decided what to
do with the various parts it reads.
