make everything use same random number generator

src/main/java/Plate.java

@@ -10,7 +10,7 @@ import java.util.*;
 public class Plate {
     private String sourceFile;
     private List<List<Integer[]>> wells;
-    private Random rand = new Random();
+    private final Random rand = BiGpairSEQ.getRand();
     private int size;
     private double error;
     private Integer[] populations;