Minor code style fixes

Author: rozza

bson/src/main/scala/org/mongodb/scala/bson/codecs/IterableCodec.scala

@@ -60,7 +60,7 @@ case class IterableCodec(registry: CodecRegistry, bsonTypeClassMap: BsonTypeClas
   override def getEncoderClass: Class[Iterable[_]] = classOf[Iterable[_]]
 
   @SuppressWarnings(Array("unchecked", "rawtypes"))
-  private def writeValue[T](writer: BsonWriter, encoderContext: EncoderContext, value: T) {
+  private def writeValue[T](writer: BsonWriter, encoderContext: EncoderContext, value: T): Unit = {
     value match {
       case isNull if value == null => writer.writeNull() // scalastyle:ignore
       case map: Map[_, _] =>
@@ -73,7 +73,7 @@ case class IterableCodec(registry: CodecRegistry, bsonTypeClassMap: BsonTypeClas
     }
   }
 
-  private def writeMap(writer: BsonWriter, map: Map[String, Any], encoderContext: EncoderContext) {
+  private def writeMap(writer: BsonWriter, map: Map[String, Any], encoderContext: EncoderContext): Unit = {
     writer.writeStartDocument()
     map.foreach(kv => {
       writer.writeName(kv._1)
@@ -82,7 +82,7 @@ case class IterableCodec(registry: CodecRegistry, bsonTypeClassMap: BsonTypeClas
     writer.writeEndDocument()
   }
 
-  private def writeIterable(writer: BsonWriter, list: Iterable[_], encoderContext: EncoderContext) {
+  private def writeIterable(writer: BsonWriter, list: Iterable[_], encoderContext: EncoderContext): Unit = {
     writer.writeStartArray()
     list.foreach(value => writeValue(writer, encoderContext, value))
     writer.writeEndArray()

driver/src/it/scala/org/mongodb/scala/gridfs/GridFSSpec.scala

@@ -116,7 +116,7 @@ class GridFSSpec extends RequiresMongoDBISpec with FuturesSpec {
   }
   // scalastyle:on cyclomatic.complexity
 
-  private def actionGridFS(action: BsonDocument, assertion: BsonDocument) {
+  private def actionGridFS(action: BsonDocument, assertion: BsonDocument): Unit = {
     if (!action.isEmpty) {
       action.getString("operation").getValue match {
         case "delete" => doDelete(action.getDocument("arguments"), assertion)
@@ -128,7 +128,7 @@ class GridFSSpec extends RequiresMongoDBISpec with FuturesSpec {
     }
   }
 
-  private def doDelete(arguments: BsonDocument, assertion: BsonDocument) {
+  private def doDelete(arguments: BsonDocument, assertion: BsonDocument): Unit = {
     val result = Try(gridFSBucket.map(_.delete(arguments.getObjectId("id").getValue)).get.futureValue)
     assertion.containsKey("error") match {
       case true => result should be a Symbol("failure")
@@ -168,7 +168,7 @@ class GridFSSpec extends RequiresMongoDBISpec with FuturesSpec {
     }
   }
 
-  private def doDownloadByName(arguments: BsonDocument, assertion: BsonDocument) {
+  private def doDownloadByName(arguments: BsonDocument, assertion: BsonDocument): Unit = {
     val outputStream: ByteArrayOutputStream = new ByteArrayOutputStream
     val options: GridFSDownloadOptions = new GridFSDownloadOptions()
     Option(arguments.get("options")).map(opts => options.revision(opts.asDocument().getInt32("revision").getValue))
@@ -187,7 +187,7 @@ class GridFSSpec extends RequiresMongoDBISpec with FuturesSpec {
   }
 
   //scalastyle:off method.length
-  private def doUpload(rawArguments: BsonDocument, assertion: BsonDocument) {
+  private def doUpload(rawArguments: BsonDocument, assertion: BsonDocument): Unit = {
 
     val arguments: BsonDocument = parseHexDocument(rawArguments, "source")