Add helper method to convert a query to a Pandas DataFrame

[davecap]

Return a DataFrame from a dataset query. It should use the query parameters if possible, such as fields (to columns), limit, etc...

dataset.query().to_dataframe()

pandas.DataFrame.from_records(list(query), columns=fields)

[jsh2134]

For querying a file

file = Object.retrieve("FILE_ID")
query = file.query()
df = pd.DataFrame(query)