Remove unused imports

Author: shoma2da

src/main/java/rx/Single.java

@@ -21,7 +21,6 @@
 import rx.annotations.Experimental;
 import rx.exceptions.Exceptions;
 import rx.exceptions.OnErrorNotImplementedException;
-import rx.functions.Action0;
 import rx.functions.Action1;
 import rx.functions.Func1;
 import rx.functions.Func2;

src/main/java/rx/internal/operators/OperatorDelay.java

@@ -17,7 +17,6 @@
 
 import java.util.concurrent.TimeUnit;
 
-import rx.Observable;
 import rx.Observable.Operator;
 import rx.Scheduler;
 import rx.Scheduler.Worker;