Microsoft flows with CRM

Hi People 

I am new to Microsoft Flows and want to Use Flows with my Dynamics CRM online trial version.

Requirement :  what i want to do is i want to save attachment of any Contact Record of CRM in File system (local storage) using Microsoft Flows.

Trigger point would be sent when a attachment has been connected to Contact.

Any detailed help would be appreciated.

Thanks 

Neeraj Agrawal

CRM developer