Updates version of DockerSpotifyClient to 3.5.13 and fixes NullPointerException

[vsuharnikov]

NullPointerException is appeared, when i try to build & publish an image to a local Docker Registry at first time (after clean):

[info] PublishLocal using Docker API 1.22
[info] Step 1 : FROM lwieske/java-8:jre-8u72-slim
[trace] Stack trace suppressed: run last server/docker:publishLocal for the full output.
[error] (server/docker:publishLocal) java.lang.NullPointerException
[error] Total time: 154 s, completed Mar 3, 2016 1:25:22 PM
> last server/docker:publishLocal
[info] PublishLocal using Docker API 1.22
[info] Step 1 : FROM lwieske/java-8:jre-8u72-slim
java.lang.NullPointerException
  at sbt.ConsoleLogger.log(ConsoleLogger.scala:195)
  at sbt.ConsoleLogger.log(ConsoleLogger.scala:185)
  at sbt.AbstractLogger.log(Logger.scala:28)
  at sbt.MultiLogger$$anonfun$dispatch$1.apply(MultiLogger.scala:35)
  at sbt.MultiLogger$$anonfun$dispatch$1.apply(MultiLogger.scala:33)
  at scala.collection.immutable.List.foreach(List.scala:318)
  at sbt.MultiLogger.dispatch(MultiLogger.scala:33)
  at sbt.MultiLogger.log(MultiLogger.scala:27)
  at sbt.Logger$class.info(Logger.scala:118)
  at sbt.AbstractLogger.info(Logger.scala:11)
  at com.typesafe.sbt.packager.docker.DockerSpotifyClientPlugin$$anonfun$publishLocalDocker$1$$anon$1.progress(DockerSpotifyClientPlugin.scala:80)
  at com.spotify.docker.client.DefaultDockerClient.build(DefaultDockerClient.java:939)
  at com.spotify.docker.client.DefaultDockerClient.build(DefaultDockerClient.java:888)
  at com.typesafe.sbt.packager.docker.DockerSpotifyClientPlugin$$anonfun$publishLocalDocker$1.apply(DockerSpotifyClientPlugin.scala:76)
  at com.typesafe.sbt.packager.docker.DockerSpotifyClientPlugin$$anonfun$publishLocalDocker$1.apply(DockerSpotifyClientPlugin.scala:65)
  at scala.Function1$$anonfun$compose$1.apply(Function1.scala:47)
  at sbt.$tilde$greater$$anonfun$$u2219$1.apply(TypeFunctions.scala:40)
  at sbt.std.Transform$$anon$4.work(System.scala:63)
  at sbt.Execute$$anonfun$submit$1$$anonfun$apply$1.apply(Execute.scala:226)
  at sbt.Execute$$anonfun$submit$1$$anonfun$apply$1.apply(Execute.scala:226)
  at sbt.ErrorHandling$.wideConvert(ErrorHandling.scala:17)
  at sbt.Execute.work(Execute.scala:235)
  at sbt.Execute$$anonfun$submit$1.apply(Execute.scala:226)
  at sbt.Execute$$anonfun$submit$1.apply(Execute.scala:226)
  at sbt.ConcurrentRestrictions$$anon$4$$anonfun$1.apply(ConcurrentRestrictions.scala:159)
  at sbt.CompletionService$$anon$2.call(CompletionService.scala:28)
  at java.util.concurrent.FutureTask.run(FutureTask.java:266)
  at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
  at java.util.concurrent.FutureTask.run(FutureTask.java:266)
  at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
  at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
  at java.lang.Thread.run(Thread.java:745)
[error] (server/docker:publishLocal) java.lang.NullPointerException

This PR fixes that issue.

[lightbend-cla-validator]

Hi @vsuharnikov,

Thank you for your contribution! We really value the time you've taken to put this together.

Before we proceed with reviewing this pull request, please sign the Typesafe Contributors License Agreement:

http://www.lightbend.com/contribute/cla

[muuki88]

Issue found: Avoid using null

[vsuharnikov]

I thought that it would be simpler than foreach, but ok, i will change it :)

[lightbend-cla-validator]

Hi @vsuharnikov,

Thank you for your contribution! We really value the time you've taken to put this together.

Before we proceed with reviewing this pull request, please sign the Typesafe Contributors License Agreement:

http://www.lightbend.com/contribute/cla

[muuki88]

Awesome, thanks :)