chore(package): update async to version 2.1.1
chore(package): update async to version 2.1.1

https://greenkeeper.io/
adube/ngeo,camptocamp/ngeo,adube/ngeo,Jenselme/ngeo,adube/ngeo,camptocamp/ngeo,ger-benjamin/ngeo,camptocamp/ngeo,ger-benjamin/ngeo,ger-benjamin/ngeo,camptocamp/ngeo,camptocamp/ngeo,Jenselme/ngeo,kalbermattenm/ngeo,kalbermattenm/ngeo,Jenselme/ngeo,adube/ngeo,Jenselme/ngeo,kalbermattenm/ngeo