Refactor mark related classes.

- Mark is an abstract class which containing its name and type
- Single Mark is a sub class of Mark which containing only one GPS location
- Gate Mark is a sub class of Mark which containing two Single Marks

#refactor #fix #story[10] #story[11] #story[12]

src/main/java/seng302/models/mark/SingleMark.java

@@ -0,0 +1,45 @@
+package seng302.models.mark;
+
+/**
+ * Represents the marker as a single mark
+ *
+ * Created by Haoming Yin (hyi25) on 17/3/2017
+ */
+public class SingleMark extends Mark {
+    private double lat;
+    private double lon;
+    private String name;
+
+
+    /**
+     * Represents a marker
+     *
+     * @param name, the name of the marker*
+     * @param lat,  the latitude of the marker
+     * @param lon,  the longitude of the marker
+     */
+    public SingleMark(String name, double lat, double lon) {
+        super(name, MarkType.SINGLE_MARK);
+        this.lat = lat;
+        this.lon = lon;
+    }
+
+    /**
+     * Represents the marker at the beginning of a leg
+     *
+     * @param name, the name of the marker
+     */
+    public SingleMark(String name) {
+        super(name, MarkType.SINGLE_MARK);
+        this.lat = 0;
+        this.lon = 0;
+    }
+
+    public double getLatitude() {
+        return this.lat;
+    }
+
+    public double getLongitude() {
+        return this.lon;
+    }
+}