async function createMemberFromStripe() {
            const initialMember = {
                name: customer.name,
                email: customer.email,
                subscribed: true,
                stripe_customer_id: customer.id
            };

            const {body} = await adminAgent
                .post(`/members/`)
                .body({members: [initialMember]})
                .expectStatus(201);
            assert.equal(body.members.length, 1, 'The member was not created');
            const member = body.members[0];
            return member;
        }
Helper method to create an existing member based on a customer in stripe (= current customer)