Added Task Adding, Removing, Editing and corrected some relatex tests. Coverage still not 100%

src/main/java/hhn/temp/project/Task.java

@@ -5,7 +5,9 @@ public class Task {
     String description;
     int taskId;
     int workerId;
-    public Task(int taskId, int workerId, String name, String description) {
+    AssignmentManager manager;
+    public Task(int taskId, int workerId, String name, String description, AssignmentManager manager) {
+        this.manager = manager;
         this.name = name;
         this.description = description;
         this.taskId = taskId;