removed warnings

src/main/java/sugui/Day06.java

@@ -1,11 +1,9 @@
 package sugui;
 
 import java.io.IOException;
-import java.lang.reflect.Array;
 import java.nio.file.Files;
 import java.nio.file.Path;
 import java.nio.file.Paths;
-import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.List;
 import java.util.stream.Collectors;

src/main/java/sugui/util/IntervalIterator.java

@@ -3,9 +3,7 @@ package sugui.util;
 import java.util.Iterator;
 
 public class IntervalIterator implements Iterator<Long> {
-    private Interval interval;
     public IntervalIterator(Interval interval) {
-        this.interval = interval;
     }
 
     @Override

src/test/java/sugui/IntervalTest.java

@@ -1,11 +1,8 @@
 package sugui;
 
-import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertTrue;
 
-import java.io.IOException;
-
 import org.junit.Test;
 
 import sugui.util.Interval;