fix(document from url): now listens to fix reaction to bad responses

ts/smartswagger.classes.smartswagger.ts

@@ -123,7 +123,12 @@ export class Smartswagger {
       headers: {
         'accept-encoding': 'application/json',
       },
+    }).catch(err => {
+      console.log(err);
     });
+    if (!documentResponse || documentResponse.status > 299) {
+      return;
+    }
     const documentString = await documentResponse.text();
     const apiDoc: IExtendedApiDoc = JSON.parse(documentString);
     console.log(`document successfully fetched!`);