Scala 2.12

[JakubKahovec]

Can you please release it for Scala 2.12 ?

[squito]

See #58

[akki]

@JakubKahovec @squito Now that #58 is merged, what else is needed for the project to be released for 2.12?

[ashishcp]

@JakubKahovec @squito @snadorp @ericmcdermidqf How do I use 0.4 in my project? 0.4-SNAPSHOT is not available on maven central.