scala 3 build

Author: pjfanning

build.sbt

@@ -7,7 +7,7 @@ organization := "com.github.swagger-akka-http"
 
 ThisBuild / scalaVersion := "2.13.6"
 
-ThisBuild / crossScalaVersions := Seq("2.11.12", "2.12.15", "2.13.6")
+ThisBuild / crossScalaVersions := Seq("2.11.12", "2.12.15", "2.13.6", "3.0.2")
 
 ThisBuild / organizationHomepage := Some(url("https://github.com/swagger-akka-http/swagger-scala-module"))