Started work on MIME parser

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.

app/inbucket/mime_test.go

@@ -0,0 +1,28 @@
+package inbucket
+
+import (
+	"bufio"
+	"net/mail"
+	"os"
+	"testing"
+)
+
+func TestSomething(t *testing.T) {
+	// Open test email for parsing
+	raw, err := os.Open("../../test-data/html-mime-attach.raw")
+	if err != nil {
+		t.Fatalf("Failed to open test data: %v", err)
+	}
+
+	// Parse email into a mail.Message object like we do
+	reader := bufio.NewReader(raw)
+	msg, err := mail.ReadMessage(reader)
+	if err != nil {
+		t.Fatalf("Failed to read message: %v", err)
+	}
+
+	_, err = ParseMIMEMessage(msg)
+	if err != nil {
+		t.Fatalf("Failed to parse mime: %v", err)
+	}
+}