Added function description for getSessionID function in RemoteWebDrvier

Author: akshayminocha5

lib/remote/RemoteWebDriver.php

@@ -372,7 +372,10 @@ public function setCommandExecutor(WebDriverCommandExecutor $executor) {
   public function getCommandExecutor() {
     return $this->executor;
   }
-
+  /**
+   * Get current selenium sessionID
+   * @return sessionID
+   */
   public function getSessionID() {
     return $this->executor->getSessionID();
   }