feat: Add exit flag

Implemented for the following commands: `play`, `stop`, `pause`, `next`, `previous` and `back`.

Example usage from the interactive mode:

```
$ itunes
iTunes: start --exit
$
```

Example usage from outside:

```
$ itunes stop --exit
iTunes:
✔ Stopped playing ♪♬
$
```

Closes #9

cli.js

@@ -14,14 +14,17 @@ vorpal
 vorpal.find('exit').description('Exit itunes-remote.');
 
 vorpal
-	.command('play', 'Start playing the current selection')
+	.command('play', 'Start playing the current selection.')
 	.alias('start')
+	.option('-E, --exit', 'exit itunes-remote after executing the command')
 	.action(function (args, callback) {
 		var self = this;
 		var spinner = ora().start();
 		itunesRemote('play', function (response) {
 			spinner.stop();
-			self.log(response);
+			if (args.options.exit) {
+				vorpal.execSync('exit');
+			}
 			callback();
 		});
 	});
@@ -90,71 +93,91 @@ vorpal
 
 vorpal
 	.command('stop', 'Stop playing the current selection')
+	.option('-E, --exit', 'exit itunes-remote after executing the command')
 	.action(function (args, callback) {
 		var self = this;
 		var spinner = ora().start();
 		itunesRemote('stop', function (response) {
 			spinner.stop();
 			self.log(response);
+			if (args.options.exit) {
+				vorpal.execSync('exit');
+			}
 			callback();
 		});
 	});
 
 vorpal
 	.command('pause', 'Pause playing the current selection')
+	.option('-E, --exit', 'exit itunes-remote after executing the command')
 	.action(function (args, callback) {
 		var self = this;
 		var spinner = ora().start();
 		itunesRemote('pause', function (response) {
 			spinner.stop();
 			self.log(response);
+			if (args.options.exit) {
+				vorpal.execSync('exit');
+			}
 			callback();
 		});
 	});
 
 vorpal
 	.command('next', 'Advance to the next track in the current playlist.')
+	.option('-E, --exit', 'exit itunes-remote after executing the command')
 	.action(function (args, callback) {
 		var self = this;
 		var spinner = ora().start();
 		itunesRemote('next', function (response) {
 			spinner.stop();
 			self.log(response);
+			if (args.options.exit) {
+				vorpal.execSync('exit');
+			}
 			callback();
 		});
 	});
 
 vorpal
 	.command('previous', 'Return to the previous track in the current playlist.')
 	.alias('prev')
+	.option('-E, --exit', 'exit itunes-remote after executing the command')
 	.action(function (args, callback) {
 		var self = this;
 		var spinner = ora().start();
 		itunesRemote('previous', function (response) {
 			spinner.stop();
 			self.log(response);
+			if (args.options.exit) {
+				vorpal.execSync('exit');
+			}
 			callback();
 		});
 	});
 
 vorpal
 	.command('back', 'Reposition to beginning of current track or go to previous track if already at start of current track.')
+	.option('-E, --exit', 'exit itunes-remote after executing the command')
 	.action(function (args, callback) {
 		var self = this;
 		var spinner = ora().start();
 		itunesRemote('back', function (response) {
 			spinner.stop();
 			self.log(response);
+			if (args.options.exit) {
+				vorpal.execSync('exit');
+			}
 			callback();
 		});
 	});
 
 vorpal
 	.command('search <searchterm>', 'Fuzzy search album, artists and songs.')
-	.option('-A, --albums', 'Limit search to albums.')
-	.option('-s, --songs', 'Limit search to songs.')
-	.option('-a, --artists', 'Limit search to artist.')
-	.option('-d, --dont-play', 'Prevent playing the search result.')
+	.option('-A, --albums', 'Limit search to albums')
+	.option('-s, --songs', 'Limit search to songs')
+	.option('-a, --artists', 'Limit search to artist')
+	.option('-d, --dont-play', 'Prevent playing the search result')
 	.action(function (args, callback) {
 		var self = this;
 		var spinner = ora('Searching …').start();

readme.md

@@ -52,15 +52,14 @@ iTunes: help
 iTunes: 
 ```
 
-But you also can pass command line arguments to quickly start a search with starting the CLI:
+**Note:**  
+You can also pass commands and options from the outside.
 
 ```
-$ itunes search nicknack -artist
-iTunes: 
-Hold on … 
-✔ Found songs by ”nicknack“ and generated a temporary playlist
-✔ Playing 44 song(s) ♪♬
-iTunes: 
+$ itunes stop --exit
+iTunes:
+✔ Stopped playing ♪♬
+$
 ```
 
 ## Thanks