Merge pull request #301 from wong2/ts-declaration-zone

Fix ConfigOptions.zone type

Author: jemygraw

.travis.yml

@@ -1,6 +1,5 @@
 language: node_js
 node_js:
-- '4'
 - '6'
 - '8'
 before_script:

index.d.ts

@@ -128,7 +128,7 @@ export declare namespace conf {
         /**
          * @default null
          */
-        zone?: 'huadong' | 'huabei' | 'huanan' | 'beimei';
+        zone?: Zone,
 
         /**
          * @default -1