add production export to testing.js

Author: dmonad

testing.js

@@ -59,6 +59,7 @@ import * as promise from './promise.js'
 import * as performance from 'lib0/performance'
 import * as traits from './traits.js'
 
+export { production } from './environment.js'
 export const extensive = env.hasConf('extensive')
 
 /* c8 ignore next */