Replace map[string]string with Context for extra options. map[string]string is essentially useless. Context can store anything

registry/options.go

@@ -2,13 +2,16 @@ package registry
 
 import (
 	"time"
+
+	"golang.org/x/net/context"
 )
 
 type Options struct {
 	Timeout time.Duration
 
-	// Other options to be used by registry implementations
-	Options map[string]string
+	// Other options for implementations of the interface
+	// can be stored in a context
+	Context context.Context
 }
 
 func Timeout(t time.Duration) Option {