Change dockerfile so that it follows dockerflow spec
Change dockerfile so that it follows dockerflow spec

jasonthomas/tls-observatory,mozilla/TLS-Observer,jasonthomas/tls-observatory,mozilla/tls-observatory,jasonthomas/tls-observatory,jasonthomas/tls-observatory,mozilla/tls-observatory,jasonthomas/tls-observatory,mozilla/tls-observatory,mozilla/tls-observatory,mozilla/tls-observatory