chore(bug): Update README + add async install

README.md

@@ -27,14 +27,26 @@ Usage example
 
 ```
 var dynamodbLocal = require("dynamodb-localhost");
-dynamodbLocal.install(); /* This is one time operation. Safe to execute multiple times which installs DynamoDB once. All the other methods depends on this. */
-dynamodbLocal.start({port: 8000});
+/* Installation is one time operation. Safe to execute multiple times which installs DynamoDB once. All the other methods depends on this. */
+dynamodbLocal.install(function() {
+  dynamodbLocal.start({port: 8000});
+}); 
+```
+
+or
+
+```
+var dynamodbLocal = require("dynamodb-localhost");
+await dynamodbLocal.install();
+
+dynamodbLocal.start();
 ```
 
 Supported methods
 
 ```
-install(callback)   To install DynamoDB Local for usage (This is one time operation unless execute remove). 'callback' function is called after installation completes (or if already installed, immediately)
+install(callback)   To install DynamoDB Local for usage (This is one time operation unless remove is executed). 'callback' function is called after installation completes (or if already installed, immediately)
+installAsync()      To install DynamoDB Local asynchronously. Otherwise identical to install.
 start(options)      To start an instance of DynamoDB Local. More information about options shown in the coming section
 stop(port)          To stop particular instance of DynamoDb Local running on an specified port
 remove(callback)    To remove DynamoDB Local instance. 'callback' function is called after removal complete.
@@ -73,4 +85,4 @@ You can also contribute by writing. Feel free to let us know if you want to publ
 
 ## Credits
 
-Bunch of thanks to doapp-ryanp who started [dynamodb-local](https://github.com/doapp-ryanp/dynamodb-local) project
+Bunch of thanks to doapp-ryanp who started [dynamodb-local](https://github.com/doapp-ryanp/dynamodb-local) project

index.js

@@ -16,6 +16,11 @@ var dynamodb = {
             callback();
         });
     },
+    installAsync: async function(path) {
+        return new Promise((resolve) => {
+            dynamodb.install(resolve, path);
+        });
+    },
     start: function(options) {
         var instance = starter.start(options, config);
         dbInstances[instance.port] = {

test/index.test.js

@@ -1,15 +1,21 @@
 const fs = require("fs");
 const utils = require("../dynamodb/utils");
 const { expect } = require("chai");
-const { install, remove } = require("../index");
+const { install, remove, installAsync } = require("../index");
 const config = require("../dynamodb/config.json");
 
 describe("install", function() {
   const installPath = `./dynamodb/${config.setup.install_path}`;
   const jarPath = `${installPath}/${config.setup.jar}`;
 
+  beforeEach(() => {
+    if (fs.existsSync(jarPath)) {
+      fs.unlinkSync(jarPath);
+    }
+  });
+
   it("downloads the jar successfully", function(done) {
-    this.timeout(10000); // 10 second timeout
+    this.timeout(60000); // 60 second timeout
 
     install(function() {
       if (fs.existsSync(jarPath)) {
@@ -18,6 +24,16 @@ describe("install", function() {
     });
   });
 
+  it("can download the jar async", async function() {
+    this.timeout(60000); // 60s timeout
+
+    await installAsync();
+
+    if (!fs.existsSync(jarPath)) {
+      throw new Error('Jar was not downloaded.');
+    }
+  });
+
   it("removes the setup files", function(done) {
     this.timeout(10000);