Merge pull request #182 from Kotlin/biginteger

Added BigInteger support

Author: Jolanrensen

kotlin-spark-api/src/main/kotlin/org/jetbrains/kotlinx/spark/api/Encoding.kt

@@ -39,6 +39,7 @@ import scala.Product
 import scala.reflect.ClassTag
 import java.beans.PropertyDescriptor
 import java.math.BigDecimal
+import java.math.BigInteger
 import java.sql.Date
 import java.sql.Timestamp
 import java.time.*
@@ -119,6 +120,7 @@ private val knownDataTypes: Map<KClass<out Any>, DataType> = mapOf(
     ByteArray::class to DataTypes.BinaryType,
     Decimal::class to DecimalType.SYSTEM_DEFAULT(),
     BigDecimal::class to DecimalType.SYSTEM_DEFAULT(),
+    BigInteger::class to DecimalType.SYSTEM_DEFAULT(),
     CalendarInterval::class to DataTypes.CalendarIntervalType,
 )