add event logo
add event logo


Former-commit-id: 958b3381ff15b323779aa73aff88f224555b3ca5
benjohnson77/devopsdays-web,joelaha/devopsdays-web,masteinhauser/devopsdays-web,joelaha/devopsdays-web,benjohnson77/devopsdays-web,masteinhauser/devopsdays-web,benjohnson77/devopsdays-web,joelaha/devopsdays-web,masteinhauser/devopsdays-web,masteinhauser/devopsdays-web,benjohnson77/devopsdays-web,joelaha/devopsdays-web