Remove usages of rxscala and replace with Java based code.

common/scala/build.gradle

@@ -81,9 +81,9 @@ dependencies {
     compile "io.zipkin.reporter2:zipkin-sender-okhttp3:2.6.1"
     compile "io.zipkin.reporter2:zipkin-reporter:2.6.1"
 
-    compile "io.reactivex:rxscala_${gradle.scala.depVersion}:0.26.5"
-    compile "io.reactivex:rxjava-reactive-streams:1.2.1"
-    compile "com.microsoft.azure:azure-cosmosdb:2.6.2"
+    compile "io.reactivex:rxjava:1.3.8"
+    compile 'io.reactivex:rxjava-reactive-streams:1.2.1'
+    compile ('com.microsoft.azure:azure-cosmosdb:2.6.2')
 
     compile ("com.lightbend.akka:akka-stream-alpakka-s3_${gradle.scala.depVersion}:1.0.1") {
         exclude group: 'org.apache.httpcomponents' //Not used as alpakka uses akka-http

common/scala/src/main/scala/org/apache/openwhisk/core/database/cosmosdb/RxObservableImplicits.scala

@@ -18,8 +18,8 @@
 package org.apache.openwhisk.core.database.cosmosdb
 
 import com.microsoft.azure.cosmosdb.{FeedResponse, Resource, ResourceResponse}
-import rx.lang.scala.JavaConverters._
 import rx.Observable
+import rx.functions.Action1
 
 import scala.collection.JavaConverters._
 import scala.concurrent.{Future, Promise}
@@ -34,8 +34,12 @@ private[cosmosdb] trait RxObservableImplicits {
      * @return the head result of the [[Observable]].
      */
     def head(): Future[T] = {
+      def toHandler[T](f: (T) => Unit): Action1[T] = new Action1[T] {
+        def call(t: T) = f(t)
+      }
+
       val promise = Promise[T]()
-      observable.asScala.single.subscribe(x => promise.success(x), e => promise.failure(e))
+      observable.single.subscribe(toHandler(promise.success), toHandler(promise.failure))
       promise.future
     }
   }
@@ -46,8 +50,8 @@ private[cosmosdb] trait RxObservableImplicits {
 
   implicit class RxScalaFeedObservable[T <: Resource](observable: Observable[FeedResponse[T]]) {
     def blockingOnlyResult(): Option[T] = {
-      val value = observable.asScala.toList.toBlocking.single
-      val results = value.head.getResults.asScala
+      val value = observable.toBlocking.single
+      val results = value.getResults.asScala
       require(results.isEmpty || results.size == 1, s"More than one result found $results")
       results.headOption
     }