implement <Flag />

[Kelbie]

I need something to easily manage users state

Only allows a user with email email@example.com see the {children}

<Flag  
    email="email@example.com"
>{children}</Flag>

Only allows an authenticated user to see the {children}

<Flag  
    isAuthenticated
>{children}</Flag>

Only allows users in the admin group to see the {children}

<Flag  
    group={["admin"]}
>{children}</Flag>

All these conditions should be composable

[Kelbie]

useFlag hook may also be useful