add vendoring

vendor/github.com/jhillyerd/enmime/parser.go

@@ -0,0 +1,22 @@
+package enmime
+
+// Parser parses MIME.
+// Default parser is a valid one.
+type Parser struct {
+	skipMalformedParts              bool
+	multipartWOBoundaryAsSinglePart bool
+}
+
+// defaultParser is a Parser with default configuration.
+var defaultParser = Parser{}
+
+// NewParser creates new parser with given options.
+func NewParser(ops ...Option) *Parser {
+	p := Parser{}
+
+	for _, o := range ops {
+		o.apply(&p)
+	}
+
+	return &p
+}