fix(crawler): Try SoupParser for ValueError exceptions.

Couldn't reproduce in tests.
Exceptions:
- All strings must be XML compatible: Unicode or ASCII, no NULL bytes or control characters
- Unicode strings with encoding declaration are not supported. Please use bytes input or XML fragments without declaration.

Example URls:
- http://www.teenvogue.com/fashion/2014-10/chanel-party
- http://www.melconway.com/Home/Committees_Paper.html