title: cy.setCookies() with domain option results in error
body: <p>This works fine</p>
  
  <pre class="lang-js prettyprint-override"><code>    beforeEach(function() {
        cy.setCookie('cookieName', 'cookieValue');
      }); 
  </code></pre>
  
  <p>But this</p>
  
  <pre class="lang-js prettyprint-override"><code>    beforeEach(function() {
            cy.setCookie('cookieName', 'cookieValue', {
              domain: 'http://example.com'
            });
          });
  </code></pre>
  
  <p>results in </p>
  
  <pre class="lang-js prettyprint-override"><code>    TypeError: Cannot read property 'replace' of undefined
  </code></pre>
  
  <p>Any hints?</p>
  
  <p>Cypress package version: 3.2.0</p>