feat: adds custom exception

Author: AmiyahJo

lesson_16/objects/objects_app/src/main/java/com/codedifferently/lesson16/amiyahjones/StudentLimitExceededException.java

@@ -0,0 +1,5 @@
+package com.codedifferently.lesson16.amiyahjones;
+
+public class StudentLimitExceededException {
+
+}

lesson_16/objects/objects_app/src/main/java/com/codedifferently/lesson16/amiyahjones/jobReadinessLab.java

@@ -45,6 +45,9 @@ public int countStudents() {
 
    public void addStudent(String studentName){
     students.add(studentName);
+        try {
+            throw new StudentLimitExceededException("The classroom is full");
+        }
    }
 
    public void printStudents() {