Fixed BS html.parser error

[jbdoster]

Really simple, Beautiful Soup was raising an issue about not explicitly specifying an HTML parser.
brahmcapoor did a similar PR, but I don't know if it ever passed travis.

So from:

To:

Please note that it still doesn't find the appropriate synonyms.

EDIT:
I'm still new to CI and travis, but I saw this error message:
nose.proxy.AssertionError: None is not an instance of <class 'list'>

Is this because each listed synonym string is under it's own individual span tag in the markup?

The code is currently scanning for child list items directly under this div container:

Either way that's why my travis tests failed.
That's for another PR I think.. Thank you.