v0.4.0

📚 PR:

• chore(package): update snazzy to version 8.0.0
• chore(package): update standard to version 12.0.0
• chore(package): update fastify to version 2.0.0
• chore(package): update lockfile package-lock.json
• ignore tap (#24)
• Add Node 12 to CI and update dependencies (#21)
• Remove package-lock (#25)
• Allow wss plugin to be customized (#22)