Add all the A tasks

Task/Averages-Simple-moving-average/Scala/averages-simple-moving-average.scala

@@ -0,0 +1,11 @@
+class MovingAverage(period: Int) {
+  private var queue = new scala.collection.mutable.Queue[Double]()
+  def apply(n: Double) = {
+    queue.enqueue(n)
+    if (queue.size > period)
+      queue.dequeue
+    queue.sum / queue.size
+  }
+  override def toString = queue.mkString("(", ", ", ")")+", period "+period+", average "+(queue.sum / queue.size)
+  def clear = queue.clear
+}