Change column of model/challenge and model/session

@@ -8,7 +8,7 @@ const ChallengeSchema=new Schema({
     endDate: {type: Object, required: true},
     durationPerSession: {type: String, required: true}, // '1d' means one day per session, '2w' means 2 weeks per session, '3m' means 3 months per session.
     goalPerSession: {type: Number, required:true}, // number of problems for one session
-    isOpen: { type: Boolean }
+    status: { type: String }
 },{
     collection: 'challenge'
 });
@@ -37,6 +37,10 @@ ChallengeSchema.methods.getGoalPerSession=function(){
     return this.goalPerSession;
 }
 
+ChallengeSchema.methods.getStatus=function(){
+    return this.status;
+}
+
 ChallengeSchema.methods.serialize=function(){
     return this.toJSON();
 }

@@ -6,7 +6,7 @@ const SessionSchema = new Schema({
     challengeId: { type: Schema.Types.ObjectId, ref: 'Challenge' },
     sessionStartDate: { type: Object },
     sessionEndDate: { type: Object },
-    isOpen: { type: Boolean  }
+    status: { type: String  }
 },{
     collection: 'session'
 });
@@ -23,8 +23,8 @@ SessionSchema.methods.getSessionEndDate=function(){
     return this.sessionEndDate;
 }
 
-SessionSchema.methods.getIsOpen=function(){
-    return this.isOpen;
+SessionSchema.methods.getStatus=function(){
+    return this.status;
 }
 
 SessionSchema.methods.serialize=function(){