Deprecation warning when using varargs in Scala 2.13.0

[flamingelk]

When creating a template using varargs e.g.

@(args: (Symbol, Any)*)

the generated code causes a deprecation warning in Scala 2.13:

Passing an explicit array value to a Scala varargs method is deprecated (since 2.13.0) and will result in a defensive copy; Use the more efficient non-copying ArraySeq.unsafeWrapArray or an explicit toIndexedSeq call

I'm not sure if this will go away when this issue is released, but if a project uses -Xfatal-warnings this blocks compilation.

[marcospereira]

Closed by #238.