Merge commit '4430658932762ead3661231492b8074f144ea4b6' into influxdb-php

Conflicts:
	lib/influxdb-php/.gitignore
	lib/influxdb-php/README.md

lib/influxdb-php/src/InfluxDB/ResultSet.php

@@ -89,6 +89,14 @@ class ResultSet
         return array_shift($series);
     }
 
+    /**
+     * @return mixed
+     */
+    public function getColumns()
+    {
+        return $this->getSeries()[0]['columns'];
+    }
+
     /**
      * @param  array $serie
      * @return array