title: Variable in outer describe block is undefined when accessing in inner describe block with Mocha test
body: <p>I've got a test suite that looks like the below:</p>
  
  <p>(Notice the <code>accountToPost</code> variable at the top (below the first <code>describe</code> block)</p>
  
  <pre><code>describe('Register Account', function () {
  
      var accountToPost;
  
      beforeEach(function (done) {
          accountToPost = {
              name: 'John',
              email: 'email@example.com',
              password: 'password123'
          };
  
          done();
      });
  
      describe('POST /account/register', function(){
  
          describe('when password_confirm is different to password', function(){
  
              //accountToPost is undefined!
              accountToPost.password_confirm = 'something'; 
  
              it('returns error', function (done) {
                //do stuff &amp; assert
              });
          });
      });
  });
  </code></pre>
  
  <p>My issue is that when I try to modify <code>accountToPost</code> in my nested describe block, it's undefined...</p>
  
  <p>What can I do to fix this?</p>