it("Testing isValid func with valid params",()=>{
        myCard = new SubscriptionCard('Pesho', 'Petrov', '00000000');
        myCard.addSubscription('120', new Date('2018-04-22'), new Date('2018-05-21'));
        myCard.addSubscription('100', new Date('2018-05-25'), new Date('2018-06-24'));

        //right date
        expect(myCard.isValid('120', new Date('2018-04-22'))).to.be.true;
        expect(myCard.isValid('120', new Date('2018-05-21'))).to.be.true;

        expect(myCard.isValid('100', new Date('2018-05-25'))).to.be.true;
        expect(myCard.isValid('100', new Date('2018-06-24'))).to.be.true;
    });