add miniTicker function (thanks mrsantran!)

```php
$api->miniTicker(function($api, $ticker) {
	print_r($ticker);
});
```
```
    [7] => Array
        (
            [symbol] => LTCUSDT
            [close] => 182.85000000
            [open] => 192.62000000
            [high] => 195.25000000
            [low] => 173.08000000
            [volume] => 238603.66451000
            [quoteVolume] => 43782422.11276660
            [eventTime] => 1520497914289
        )

    [8] => Array
        (
            [symbol] => ICXBTC
            [close] => 0.00029790
            [open] => 0.00030550
            [high] => 0.00031600
            [low] => 0.00026850
            [volume] => 8468620.53000000
            [quoteVolume] => 2493.60935828
            [eventTime] => 1520497915200
        )
```

php-binance-api.php

@@ -639,47 +639,31 @@ public function keepAlive() {
 		$loop->run();
 	}
 
-	// Issues userDataStream token and keepalive, subscribes to userData WebSocket
-	public function userData(&$balance_callback, &$execution_callback = false) {
-		$response = $this->apiRequest("v1/userDataStream", "POST");
-		$listenKey = $this->options['listenKey'] = $response['listenKey'];
-		$this->info['balanceCallback'] = $balance_callback;
-		$this->info['executionCallback'] = $execution_callback;
-		\Ratchet\Client\connect('wss://stream.binance.com:9443/ws/'.$listenKey)->then(function($ws) {
-			$ws->on('message', function($data) use($ws) {
-				$json = json_decode($data);
-				$type = $json->e;
-				if ( $type == "outboundAccountInfo") {
-					$balances = $this->balanceHandler($json->B);
-					$this->info['balanceCallback']($this, $balances);
-				} elseif ( $type == "executionReport" ) {
-					$report = $this->executionHandler($json);
-					if ( $this->info['executionCallback'] ) {
-						$this->info['executionCallback']($this, $report);
-					}
-				}
-			});
-			$ws->on('close', function($code = null, $reason = null) {
-				echo "userData: WebSocket Connection closed! ({$code} - {$reason})".PHP_EOL;
-			});
-		}, function($e) {
-			echo "userData: Could not connect: {$e->getMessage()}".PHP_EOL;
-		});
-	}
-
-	public function miniTicker($callback)
-	{
-		\Ratchet\Client\connect('wss://stream2.binance.com:9443/ws/!miniTicker@arr@3000ms')
+	public function miniTicker($callback) {
+		\Ratchet\Client\connect('wss://stream2.binance.com:9443/ws/!miniTicker@arr@1000ms')
 			->then(function($ws) use($callback) {
 			    $ws->on('message', function($data) use($ws, $callback) {
-				$json = json_decode($data);
-				call_user_func($callback, $this, $json);
-			    });
-			    $ws->on('close', function($code = null, $reason = null) {
-				echo "ticker: WebSocket Connection closed! ({$code} - {$reason})" . PHP_EOL;
+					$json = json_decode($data, true);
+					$markets = [];
+					foreach ( $json as $obj ) {
+						$markets[] = [
+							"symbol" => $obj['s'],
+							"close" => $obj['c'],
+							"open" => $obj['o'],
+							"high" => $obj['h'],
+							"low" => $obj['l'],
+							"volume" => $obj['v'],
+							"quoteVolume" => $obj['q'],
+							"eventTime" => $obj['E']
+						];
+					}
+					call_user_func($callback, $this, $symbols);
+				    });
+				    $ws->on('close', function($code = null, $reason = null) {
+					echo "miniticker: WebSocket Connection closed! ({$code} - {$reason})" . PHP_EOL;
 			    });
 			}, function($e) {
-			    echo "ticker: Could not connect: {$e->getMessage()}" . PHP_EOL;
+			    echo "miniticker: Could not connect: {$e->getMessage()}" . PHP_EOL;
 			});
 	}
 }