More readme fixes

Author: AmitBu

README.md

@@ -21,7 +21,7 @@ $sn = new SecureNative('YOUR_API_KEY', new SecureNativeOptions());
 ## Event tracking
 
 ```
-secureNative::track(array(
+$sn->track(array(
     'event_type' => EventTypes::LOG_IN,
     'ip' => '127.0.0.1',
     'userAgent' => 'Mozilla/5.0 (iPad; U; CPU OS 3_2_1 like Mac OS X; en-us) AppleWebKit/531.21.10 (KHTML, like Gecko) Mobile/7B405',
@@ -32,7 +32,7 @@ secureNative::track(array(
 
 or
 
-secureNative::track(array(
+$sn->track(array(
     EventOptions::EVENT_EVENT_TYPE => EventTypes::LOG_IN,
     EventOptions::EVENT_IP => '127.0.0.1',
     EventOptions::USER_AGENT => 'Mozilla/5.0 (iPad; U; CPU OS 3_2_1 like Mac OS X; en-us) AppleWebKit/531.21.10 (KHTML, like Gecko) Mobile/7B405',