Add support for address lookup without the borough

[Andrew-Dickinson]

Right now we require a full address (including at least the borough name). Most people in the support channel seem to provide their address without the borough though

>>> dc.address_to_nn("9459 Oak St, Brooklyn NY")
5107
>>> dc.address_to_nn("9459 Oak St, Brooklyn")
5107
>>> dc.address_to_nn("9459 Oak St")
Traceback (most recent call last):
  File "C:\Users\fortk\AppData\Local\Programs\Python\Python38\lib\code.py", line 90, in runcode
    exec(code, self.locals)
  File "<input>", line 1, in <module>
  File "C:\Users\fortk\PycharmProjects\nycmesh-support-bot\mesh_database_client\database.py", line 126, in address_to_nn
    location = geocode_result[0]['geometry']['location']
IndexError: list index out of range