Remove Scala 2.10.x support; Add 2.12.x suppport

Author: AndrewJo

build.sbt

@@ -4,11 +4,12 @@ name := "spark-cassandra-connection-factory"
 organization := "co.verdigris.spark"
 version := "0.4.0"
 scalaVersion := "2.11.12"
-crossScalaVersions := Seq("2.10.7", "2.11.12", "2.12.12")
+crossScalaVersions := Seq("2.11.12", "2.12.12")
 
 lazy val scalaTest = "org.scalatest" %% "scalatest" % "3.0.0"
 
 libraryDependencies += "org.apache.spark" %% "spark-core" % "2.3.2" % "provided"
+libraryDependencies += "org.apache.spark" %% "spark-sql" % "2.3.2" % "provided"
 libraryDependencies += "com.datastax.spark" %% "spark-cassandra-connector" % "2.3.2" % "provided"
 libraryDependencies += "co.verdigris.ssl" %% "ssllib" % "1.1.2"
 libraryDependencies += scalaTest % Test