Merge pull request #18 from seokoka/patch-1

Changed cast from int to float for message timestamp.

src/Gelf/Message.php

@@ -244,7 +244,7 @@ public function toArray()
             'full_message' => $this->getFullMessage(),
             'host' => $this->getHost(),
             // Ensure numeric values.
-            'timestamp' => (int)$this->getTimestamp(),
+            'timestamp' => (float)$this->getTimestamp(),
             'level' => (int)$this->getLevel(),
           )
         );