fix(callAPIMethod): ff & safari(isomorphic-fetch) doesn't support response.body

Author: Alexander Vakhitov

src/callAPIMethod.js

@@ -26,13 +26,16 @@ export default function callAPI(
 
     return fetch(url, {...defaults.fetchOptions, ...fetchOptions, ...options})
         .then( result => {
-            const promiseCallback = result.body ? result[method]() : new Promise(resolve => resolve(result.body));
+            const promiseCallback = result[method]();
 
             if (result.ok) {
                 return promiseCallback;
             }
 
             return promiseCallback
+                .catch( () => {
+                    throw new APIError(result.status, result.statusText);
+                })
                 .then( body => {
                     throw new APIError(result.status, result.statusText, body);
                 });