Refactor plate to fill its own wells in its constructor

src/main/java/PlateFileReader.java

@@ -56,11 +56,8 @@ public class PlateFileReader {
 
     }
 
-    public List<List<Integer[]>> getWells() {
-        return wells;
+    public Plate getSamplePlate() {
+        return new Plate(filename, wells);
     }
 
-    public String getFilename() {
-        return filename;
-    }
 }