Merge branch 'master' into params-serialization

Author: developit

src/index.js

@@ -199,7 +199,8 @@ export default (function create(defaults) {
 		return fetchFunc(url, {
 			method: options.method,
 			body: data,
-			headers: deepMerge(options.headers, customHeaders, true)
+			headers: deepMerge(options.headers, customHeaders, true),
+			credentials: options.withCredentials && 'include'
 		}).then((res) => {
 			let i;
 			for (i in res) {