Ensure context bindings are used for Run().

callbacks.go

@@ -23,10 +23,11 @@ func (b bindings) clone() bindings {
 	return out
 }
 
-func (b bindings) merge(other bindings) {
+func (b bindings) merge(other bindings) bindings {
 	for k, v := range other {
 		b[k] = v
 	}
+	return b
 }
 
 func getMethod(value reflect.Value, name string) reflect.Value {

context.go

@@ -501,7 +501,7 @@ func (c *Context) Run(bindings ...interface{}) (err error) {
 	if err != nil {
 		return err
 	}
-	binds := c.Kong.bindings.clone().add(bindings...).add(c)
+	binds := c.Kong.bindings.clone().add(bindings...).add(c).merge(c.bindings)
 	return callMethod("Run", node.Target, method, binds)
 }