Disable FlatMapObservableTest that is intermittently failing

The failure will be investigated in JAVA-4413

Author: jyemin

driver-scala/src/test/scala/org/mongodb/scala/internal/FlatMapObservableTest.scala

@@ -17,6 +17,7 @@
 package org.mongodb.scala.internal
 
 import org.mongodb.scala.{ BaseSpec, Observable, Observer }
+import org.scalatest.Assertions
 import org.scalatest.concurrent.{ Eventually, Futures }
 
 import java.util.concurrent.atomic.AtomicInteger
@@ -25,6 +26,8 @@ import scala.concurrent.{ Future, Promise }
 
 class FlatMapObservableTest extends BaseSpec with Futures with Eventually {
   "FlatMapObservable" should "only complete once" in {
+    Assertions.cancel("Temporarily skipping this test")
+
     val p = Promise[Unit]()
     val completedCounter = new AtomicInteger(0)
     Observable(1 to 100)