get_ticker_details doesn't include the date param #320

Describe the bug
RESTClient.get_ticker_details calls self._get with params=params, rather than params=self._get_params(...), and thus ignores the date param specified by the caller

To Reproduce

from polygon import RESTClient

client = RESTClient("<API token>")

client.get_ticker_details("AAPL", date="2020-10-01")

Expected behavior
Should perform the API request with a query param ?date=2020-10-01

Additional context
PR incoming 😃