Add thin Ledger default wrapper (#212)

* Add thin Ledger default wrapper

* move showAddress confirmFlag

* Add node hid support

* export Ledger

* addHardware

* libusb dep for CircleCI

* Cleanup typings (buffer expected)

packages/ui-keyring/src/index.ts

@@ -5,7 +5,7 @@
 import { assertSingletonPackage } from '@polkadot/util';
 
 import keyring, { Keyring } from './Keyring';
-import { openLedger } from './ledger';
+import Ledger from './ledger';
 
 assertSingletonPackage('@polkadot/ui-keyring');
 
@@ -13,5 +13,5 @@ export default keyring;
 
 export {
   Keyring,
-  openLedger
+  Ledger
 };