travis: Remove openjdk8, add openjdk(9|11)
travis: Remove openjdk8, add openjdk(9|11)

Flowdalic/Smack,igniterealtime/Smack,vanitasvitae/Smack,Flowdalic/Smack,igniterealtime/Smack,igniterealtime/Smack,vanitasvitae/Smack,Flowdalic/Smack,vanitasvitae/Smack