[AIRFLOW-545] Add Bloc as Airflow user[]

Closes apache#1819 from dpaola2/patch-1
https://issues.apache.org/jira/browse/AIRFLOW-545

README.md

@@ -86,6 +86,7 @@ Currently **officially** using Airflow:
 1. [AltX](https://www.getaltx.com/about) [[@pedromduarte](https://github.com/pedromduarte)]
 1. [Apigee](https://apigee.com) [[@btallman](https://github.com/btallman)]
 1. [Bellhops](https://github.com/bellhops)
+1. [Bloc](https://www.bloc.io) [[@dpaola2](https://github.com/dpaola2)]
 1. BlueApron [[@jasonjho](https://github.com/jasonjho) & [@matthewdavidhauser](https://github.com/matthewdavidhauser)]
 1. [Blue Yonder](http://www.blue-yonder.com) [[@blue-yonder](https://github.com/blue-yonder)]
 1. [Clairvoyant](https://clairvoyantsoft.com) [@shekharv](https://github.com/shekharv)