fix error example

WhatAKitty · WhatAKitty · commit 36dc5c52ffc9 · 2017-04-17T11:39:40.000+08:00
diff --git a/README.md b/README.md
@@ -35,7 +35,7 @@ index.js
 import FetchMock from 'react-native-fetch-mock';
 
 if (__dev__) {
-  global.fetch = new FetchMock(require('path/to/mocks/directory'));
+  global.fetch = new FetchMock(require('path/to/mocks/directory')).fetch;
 }
 
 // if __dev__ is true, it will back the data you defined in mock directory

Original file line number	Diff line number	Diff line change
`@@ -35,7 +35,7 @@ index.js`
`35`	`35`	`import FetchMock from 'react-native-fetch-mock';`
`36`	`36`
`37`	`37`	`if (__dev__) {`
`38`		`- global.fetch = new FetchMock(require('path/to/mocks/directory'));`
	`38`	`+ global.fetch = new FetchMock(require('path/to/mocks/directory')).fetch;`
`39`	`39`	`}`
`40`	`40`
`41`	`41`	`// if __dev__ is true, it will back the data you defined in mock directory`