Add rxscala dependancy

Author: pulsation

build.sbt

@@ -1,10 +1,15 @@
 import android.Keys._                                                                                                                                                                                                                         
-
 android.Plugin.androidBuild
 
 name := "ephedra-android"
 
+libraryDependencies ++= Seq(
+  "com.netflix.rxjava" % "rxjava-scala" % "0.15.1"
+)
+
 proguardOptions in Android ++= Seq(
+  "-dontwarn rx.operators.OperationParallelMergeTest",
+  "-dontwarn rx.subjects.UnsubscribeTester",
   "-keep class android.widget.TextView"
 )