Add test case for #37: new tokens are invalid in the second they are created
Add test case for #37: new tokens are invalid in the second they are created

Verify() truncates the time in the `iat` field and Now() to the nearest second when comparing so the `iat` claim fails because Now() is not after `iat` when checking the validity of the token within the same second.

lestrrat/go-jwx,lestrrat/go-jwx