'Long varchar' not supported by VerticaDialect.get_columns

[vhermecz]

Calling Table(table, meta, autoload=True, autoload_with=engine) fails on Vertica tables with Long varchar fields, as ischema_names misses entry for 'LONG VARCHAR'.

...
    Table(table, meta, autoload=True, autoload_with=engine)
  File "/home/isc/envs/datasources/local/lib/python2.7/site-packages/sqlalchemy/sql/schema.py", line 352, in __new__
    table._init(name, metadata, *args, **kw)
  File "/home/isc/envs/datasources/local/lib/python2.7/site-packages/sqlalchemy/sql/schema.py", line 425, in _init
    self._autoload(metadata, autoload_with, include_columns)
  File "/home/isc/envs/datasources/local/lib/python2.7/site-packages/sqlalchemy/sql/schema.py", line 437, in _autoload
    self, include_columns, exclude_columns
  File "/home/isc/envs/datasources/local/lib/python2.7/site-packages/sqlalchemy/engine/base.py", line 1663, in run_callable
    return conn.run_callable(callable_, *args, **kwargs)
  File "/home/isc/envs/datasources/local/lib/python2.7/site-packages/sqlalchemy/engine/base.py", line 1190, in run_callable
    return callable_(self, *args, **kwargs)
  File "/home/isc/envs/datasources/local/lib/python2.7/site-packages/sqlalchemy/engine/default.py", line 355, in reflecttable
    return insp.reflecttable(table, include_columns, exclude_columns)
  File "/home/isc/envs/datasources/local/lib/python2.7/site-packages/sqlalchemy/engine/reflection.py", line 463, in reflecttable
    for col_d in self.get_columns(table_name, schema, **table.dialect_kwargs):
  File "/home/isc/envs/datasources/local/lib/python2.7/site-packages/sqlalchemy/engine/reflection.py", line 277, in get_columns
    **kw)
  File "<string>", line 2, in get_columns
  File "/home/isc/envs/datasources/local/lib/python2.7/site-packages/sqlalchemy/engine/reflection.py", line 53, in cache
    ret = fn(self, con, *args, **kw)
  File "/home/isc/envs/datasources/local/lib/python2.7/site-packages/sqlalchemy_vertica/base.py", line 153, in get_columns
    coltype = self.ischema_names[dtype]
KeyError: u'LONG VARCHAR'