Add sshchat dependencies in vendor

vendor/github.com/shazow/rateio/reader.go

@@ -0,0 +1,25 @@
+package rateio
+
+import "io"
+
+type reader struct {
+	io.Reader
+	Limiter
+}
+
+// Read reads data into p.
+// Returns ErrRateExceeded error if our specified read is exceeded.
+func (r *reader) Read(p []byte) (n int, err error) {
+	n, err = r.Reader.Read(p)
+	if err != nil {
+		return
+	}
+
+	err = r.Limiter.Count(n)
+	return
+}
+
+// NewReader proxies an io.Reader but keeps track of bytes read based on our Limiter.
+func NewReader(r io.Reader, limiter Limiter) io.Reader {
+	return &reader{r, limiter}
+}