Add getLedgerVersion and unit test

src/api/index.js

@@ -6,6 +6,7 @@ const disconnect = server.disconnect;
 const getServerInfo = server.getServerInfo;
 const getFee = server.getFee;
 const isConnected = server.isConnected;
+const getLedgerVersion = server.getLedgerVersion;
 const getTransaction = require('./ledger/transaction');
 const getTransactions = require('./ledger/transactions');
 const getTrustlines = require('./ledger/trustlines');
@@ -34,6 +35,7 @@ RippleAPI.prototype = {
   isConnected,
   getServerInfo,
   getFee,
+  getLedgerVersion,
 
   getTransaction,
   getTransactions,

src/api/server/server.js

@@ -36,10 +36,15 @@ function getFee() {
   return common.dropsToXrp(this.remote.createTransaction()._computeFee());
 }
 
+function getLedgerVersion() {
+  return this.remote.getLedgerSequence();
+}
+
 module.exports = {
-  connect: connect,
-  disconnect: disconnect,
-  isConnected: isConnected,
-  getServerInfo: getServerInfo,
-  getFee: getFee
+  connect,
+  disconnect,
+  isConnected,
+  getServerInfo,
+  getFee,
+  getLedgerVersion
 };

test/api-test.js

@@ -190,4 +190,8 @@ describe('RippleAPI', function() {
     this.api.getPathFind(pathfind,
       _.partial(checkResult, getPathFindResponse, done));
   });
+
+  it('getLedgerVersion', function() {
+    assert.strictEqual(this.api.getLedgerVersion(), 8819952);
+  });
 });