interface name consistency

src/lib/observable/DummyObservable.hx

@@ -2,7 +2,7 @@ package lib.observable;
 
 using tink.CoreApi;
 
-class DummyObservable<T> implements Observable<T> {
+class DummyObservable<T> implements IObservable<T> {
 	private var value:T;
 
 	private function new(value:T) {
@@ -21,7 +21,7 @@ class DummyObservable<T> implements Observable<T> {
 		return null;
 	}
 
-	public static function dummy<T>(value:T):Observable<T> {
+	public static function dummy<T>(value:T):IObservable<T> {
 		return new DummyObservable<T>(value);
 	}
 }