Bring back Scala 2.10 support

Author: kciesielski

build.sbt

@@ -6,7 +6,7 @@ val slf4jLog4jArtifact = "slf4j-log4j12"
 lazy val commonSettings = Seq(
   name := "scalatest-embedded-kafka",
   organization := "net.manub",
-  scalaVersion := "2.11.8",
+  crossScalaVersions := Seq("2.10.6", "2.11.8"),
   homepage := Some(url("https://github.com/manub/scalatest-embedded-kafka")),
   parallelExecution in Test := false,
   libraryDependencies ++= Seq(