[AIRFLOW-1106] Add Groupalia/Letsbonus to the ReadMe

Closes apache#2239 from jesusfcr/docs

README.md

@@ -107,6 +107,7 @@ Currently **officially** using Airflow:
 1. [Gentner Lab](http://github.com/gentnerlab) [[@neuromusic](https://github.com/neuromusic)]
 1. [Glassdoor](https://github.com/Glassdoor) [[@syvineckruyk](https://github.com/syvineckruyk)]
 1. [GovTech GDS](https://gds-gov.tech) [[@chrissng](https://github.com/chrissng) & [@datagovsg](https://github.com/datagovsg)]
+1. [Groupalia](http://es.groupalia.com) [[@jesusfcr](https://github.com/jesusfcr)]
 1. [Gusto](https://gusto.com) [[@frankhsu](https://github.com/frankhsu)]
 1. [Handshake](https://joinhandshake.com/) [[@mhickman](https://github.com/mhickman)]
 1. [Handy](http://www.handy.com/careers/73115?gh_jid=73115&gh_src=o5qcxn) [[@marcintustin](https://github.com/marcintustin) / [@mtustin-handy](https://github.com/mtustin-handy)]
@@ -122,6 +123,7 @@ Currently **officially** using Airflow:
 1. [Kogan.com](https://github.com/kogan) [[@geeknam](https://github.com/geeknam)]
 1. [Lemann Foundation](http://fundacaolemann.org.br) [[@fernandosjp](https://github.com/fernandosjp)]
 1. [LendUp](https://www.lendup.com/) [[@lendup](https://github.com/lendup)]
+1. [Letsbonus](http://www.letsbonus.com) [[@jesusfcr](https://github.com/jesusfcr)]
 1. [liligo](http://liligo.com/) [[@tromika](https://github.com/tromika)]
 1. [LingoChamp](http://www.liulishuo.com/) [[@haitaoyao](https://github.com/haitaoyao)]
 1. [Lucid](http://luc.id) [[@jbrownlucid](https://github.com/jbrownlucid) & [@kkourtchikov](https://github.com/kkourtchikov)]