Starting scalac patch infrastructure

Author: Devon Stewart

build.sbt

@@ -7,10 +7,15 @@ import sbtcrossproject.CrossType
 val Org = "org.scoverage"
 val ScalatestVersion = "3.1.1"
 
+val bin212 = Seq("2.12.13", "2.12.12", "2.12.11", "2.12.10")
+val bin213 = Seq("2.13.4", "2.13.3", "2.13.2", "2.13.1", "2.13.0")
+
 val appSettings = Seq(
     organization := Org,
-    scalaVersion := "2.12.10",
-    crossScalaVersions := Seq("2.12.10", "2.13.4"),
+    scalaVersion := "2.12.13",
+    crossScalaVersions := bin212 ++ bin213,
+    crossVersion := CrossVersion.full,
+    crossTarget := target.value / s"scala-${scalaVersion.value}",
     fork in Test := false,
     publishMavenStyle := true,
     publishArtifact in Test := false,