Fix HTML5 parsing errors
Fix HTML5 parsing errors

When ran ```python create_hit.py``` with  "tasks/coco_crowd_labeling.html," I got this error:
```
create HIT on sandbox
Traceback (most recent call last):
  File "/home2/grad97/myh/git/coco-ui/create_hit.py", line 60, in <module>
    Question = create_xml_question(html_text),
  File "/usr/lib/python2.7/site-packages/botocore/client.py", line 324, in _api_call
    return self._make_api_call(operation_name, kwargs)
  File "/usr/lib/python2.7/site-packages/botocore/client.py", line 622, in _make_api_call
    raise error_class(parsed_response, operation_name)
ClientError: An error occurred (ParameterValidationError) when calling the CreateHIT operation: There was an error parsing the HTML5 data in your request.  Please make sure the data is well-formed and validates as HTML5. Details: Errors: <! [109,8] An \u201cbody\u201d start tag seen but an element of the same type was already open. !> <! [159,26] No space between attributes. !> Invalid content: 
<!DOCTYPE html>
<html lang="en">
  <head>
...
```
After fixing the bugs in coco_crowd_labeling.html, ```python create_hit.py``` runs successfully.
tylin/coco-ui,tylin/coco-ui,tylin/coco-ui