docs(tutorial/3 - Filtering Repeaters): correction to e2e test

Line 174, you need to declare the variable query for the test to work.
This is not  the proper way to fix this either.

`phoneList` and `query` are initialized at the top of the test-suite (which isn't right as they should be initialized for every test).

Something like this would be more appropriate I guess:

      describe('Phone list view', function() {
        var phoneList;
        var query;
        
        beforeEach(function() {
          browser.get('app/index.html');
          phoneList = element.all(by.repeater('phone in phones'));
          query = element(by.model('query'));
        });
    
        it('should filter the phone list as a user types into the search box', function() {
          ...
        });
    
        it('should display the current filter value in the title bar', function() {
          query.clear();
          ...
        });
      });