title: Use Azure AD token to authenticate with Azure DevOps
body: <p>I'm writing a web API.  One of the things it does is hit Azure DevOps using the Team Foundation Core DLLs.  As we are backed by Azure AD (Azure Active Directory) I was thinking that I could have my app authenticate against Azure AD and use that token/authorization for Azure DevOps.  This isn't the only service that it is going to authenticate with.  Can I do this?  what other ways can I achieve this goal?  I don't want to prompt the user to authorize against Azure AD each time it goes to hit a unique service, especially as they are all backed by Azure AD.</p>