change method permissions(): from belongsTo to belongsToMany
add 'jobseeker_id' to $fillable
implement applyToJob() method
implement test_applying_to_job() method
add foreign key 'member_id' to member() method
add "user_assigned_by" and "user_assigned_to" fields to $fillable
add 'job_application_id', 'stage_id', 'member_id' fields to $fillable
split tasks() method to taskAssignedBySelf() and tasksAssignedToOthers
implement test_creating_member_note() and  test_creating_member_task()