change dep to go module

vendor/github.com/olivere/elastic/CONTRIBUTORS

@@ -32,6 +32,7 @@ Bruce Zhou [@brucez-isell](https://github.com/brucez-isell)
 Carl Dunham [@carldunham](https://github.com/carldunham)
 César Jiménez [@cesarjimenez](https://github.com/cesarjimenez)
 cforbes [@cforbes](https://github.com/cforbes)
+張泰瑋(Chang Tai Wei) [@david30907d](https://github.com/david30907d)
 Chris M [@tebriel](https://github.com/tebriel)
 Chris Rice [@donutmonger](https://github.com/donutmonger)
 Claudiu Olteanu [@claudiuolteanu](https://github.com/claudiuolteanu)
@@ -44,9 +45,11 @@ Corey Scott [@corsc](https://github.com/corsc)
 Daniel Barrett [@shendaras](https://github.com/shendaras)
 Daniel Heckrath [@DanielHeckrath](https://github.com/DanielHeckrath)
 Daniel Imfeld [@dimfeld](https://github.com/dimfeld)
+Daniel Santos [@danlsgiga](https://github.com/danlsgiga)
 David Emanuel Buchmann [@wuurrd](https://github.com/wuurrd)
 Dwayne Schultz [@myshkin5](https://github.com/myshkin5)
 Ellison Leão [@ellisonleao](https://github.com/ellisonleao)
+Erik Grinaker [@erikgrinaker](https://github.com/erikgrinaker)
 Erwin [@eticzon](https://github.com/eticzon)
 Eugene Egorov [@EugeneEgorov](https://github.com/EugeneEgorov)
 Evan Shaw [@edsrzf](https://github.com/edsrzf)