vendor dependencies with dep

vendor/github.com/go-chi/chi/middleware/compress18.go

@@ -0,0 +1,15 @@
+// +build go1.8
+
+package middleware
+
+import (
+	"errors"
+	"net/http"
+)
+
+func (w *maybeCompressResponseWriter) Push(target string, opts *http.PushOptions) error {
+	if ps, ok := w.w.(http.Pusher); ok {
+		return ps.Push(target, opts)
+	}
+	return errors.New("chi/middleware: http.Pusher is unavailable on the writer")
+}