Fixed unresolved dependency error

Fixed this.

```
$ sbt
[info] Loading global plugins from /Users/toshi/.sbt/0.13/plugins
[info] Loading project definition from /Users/toshi/work/scala/workbench-example-app/project
[info] Updating {file:/Users/toshi/work/scala/workbench-example-app/project/}workbench-example-app-build...
[info] Resolving com.typesafe.play#play-json_2.10;2.2.0-RC1 ...
[warn]  module not found: com.typesafe.play#play-json_2.10;2.2.0-RC1
[warn] ==== typesafe-ivy-releases: tried
[warn]   http://repo.typesafe.com/typesafe/ivy-releases/com.typesafe.play/play-json_2.10/2.2.0-RC1/ivys/ivy.xml
[warn] ==== sbt-plugin-releases: tried
[warn]   http://repo.scala-sbt.org/scalasbt/sbt-plugin-releases/com.typesafe.play/play-json_2.10/2.2.0-RC1/ivys/ivy.xml
[warn] ==== local: tried
[warn]   /Users/toshi/.ivy2/local/com.typesafe.play/play-json_2.10/2.2.0-RC1/ivys/ivy.xml
[warn] ==== public: tried
[warn]   http://repo1.maven.org/maven2/com/typesafe/play/play-json_2.10/2.2.0-RC1/play-json_2.10-2.2.0-RC1.pom
[info] Resolving org.fusesource.jansi#jansi;1.4 ...
[warn]  ::::::::::::::::::::::::::::::::::::::::::::::
[warn]  ::          UNRESOLVED DEPENDENCIES         ::
[warn]  ::::::::::::::::::::::::::::::::::::::::::::::
[warn]  :: com.typesafe.play#play-json_2.10;2.2.0-RC1: not found
[warn]  ::::::::::::::::::::::::::::::::::::::::::::::
sbt.ResolveException: unresolved dependency: com.typesafe.play#play-json_2.10;2.2.0-RC1: not found
        at sbt.IvyActions$.sbt$IvyActions$$resolve(IvyActions.scala:213)
        at sbt.IvyActions$$anonfun$update$1.apply(IvyActions.scala:122)
        at sbt.IvyActions$$anonfun$update$1.apply(IvyActions.scala:121)
        at sbt.IvySbt$Module$$anonfun$withModule$1.apply(Ivy.scala:116)
        at sbt.IvySbt$Module$$anonfun$withModule$1.apply(Ivy.scala:116)
        at sbt.IvySbt$$anonfun$withIvy$1.apply(Ivy.scala:104)
        at sbt.IvySbt.sbt$IvySbt$$action$1(Ivy.scala:51)
        at sbt.IvySbt$$anon$3.call(Ivy.scala:60)
        at xsbt.boot.Locks$GlobalLock.withChannel$1(Locks.scala:98)
        at xsbt.boot.Locks$GlobalLock.xsbt$boot$Locks$GlobalLock$$withChannelRetries$1(Locks.scala:81)
        at xsbt.boot.Locks$GlobalLock$$anonfun$withFileLock$1.apply(Locks.scala:102)
        at xsbt.boot.Using$.withResource(Using.scala:11)
        at xsbt.boot.Using$.apply(Using.scala:10)
        at xsbt.boot.Locks$GlobalLock.ignoringDeadlockAvoided(Locks.scala:62)
        at xsbt.boot.Locks$GlobalLock.withLock(Locks.scala:52)
        at xsbt.boot.Locks$.apply0(Locks.scala:31)
        at xsbt.boot.Locks$.apply(Locks.scala:28)
        at sbt.IvySbt.withDefaultLogger(Ivy.scala:60)
        at sbt.IvySbt.withIvy(Ivy.scala:101)
        at sbt.IvySbt.withIvy(Ivy.scala:97)
        at sbt.IvySbt$Module.withModule(Ivy.scala:116)
        at sbt.IvyActions$.update(IvyActions.scala:121)
        at sbt.Classpaths$$anonfun$sbt$Classpaths$$work$1$1.apply(Defaults.scala:1144)
        at sbt.Classpaths$$anonfun$sbt$Classpaths$$work$1$1.apply(Defaults.scala:1142)
        at sbt.Classpaths$$anonfun$doWork$1$1$$anonfun$73.apply(Defaults.scala:1165)
        at sbt.Classpaths$$anonfun$doWork$1$1$$anonfun$73.apply(Defaults.scala:1163)
        at sbt.Tracked$$anonfun$lastOutput$1.apply(Tracked.scala:35)
        at sbt.Classpaths$$anonfun$doWork$1$1.apply(Defaults.scala:1167)
        at sbt.Classpaths$$anonfun$doWork$1$1.apply(Defaults.scala:1162)
        at sbt.Tracked$$anonfun$inputChanged$1.apply(Tracked.scala:45)
        at sbt.Classpaths$.cachedUpdate(Defaults.scala:1170)
        at sbt.Classpaths$$anonfun$updateTask$1.apply(Defaults.scala:1135)
        at sbt.Classpaths$$anonfun$updateTask$1.apply(Defaults.scala:1113)
        at scala.Function1$$anonfun$compose$1.apply(Function1.scala:47)
        at sbt.$tilde$greater$$anonfun$$u2219$1.apply(TypeFunctions.scala:42)
        at sbt.std.Transform$$anon$4.work(System.scala:64)
        at sbt.Execute$$anonfun$submit$1$$anonfun$apply$1.apply(Execute.scala:237)
        at sbt.Execute$$anonfun$submit$1$$anonfun$apply$1.apply(Execute.scala:237)
        at sbt.ErrorHandling$.wideConvert(ErrorHandling.scala:18)
        at sbt.Execute.work(Execute.scala:244)
        at sbt.Execute$$anonfun$submit$1.apply(Execute.scala:237)
        at sbt.Execute$$anonfun$submit$1.apply(Execute.scala:237)
        at sbt.ConcurrentRestrictions$$anon$4$$anonfun$1.apply(ConcurrentRestrictions.scala:160)
        at sbt.CompletionService$$anon$2.call(CompletionService.scala:30)
        at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:334)
        at java.util.concurrent.FutureTask.run(FutureTask.java:166)
        at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:471)
        at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:334)
        at java.util.concurrent.FutureTask.run(FutureTask.java:166)
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
        at java.lang.Thread.run(Thread.java:722)
[error] (*:update) sbt.ResolveException: unresolved dependency: com.typesafe.play#play-json_2.10;2.2.0-RC1: not found
```