Add FleetDM to list of adoptions

Author: joshuagl

data/adoptions.yaml

@@ -23,6 +23,8 @@ main:
   tag: Notary
 - url: https://foundries.io/insights/blog/2018/05/25/ota-part-1/
   tag: foundriesio
+- url: https://blog.fleetdm.com/fleet-3-10-0-released-with-agent-auto-updates-beta-f4dd61be001d
+  tag: fleetdm
 ongoing:
 - url: https://www.well-typed.com/blog/2015/04/improving-hackage-security
   tag: Haskell