BUG: Fix crash using to_csv with QUOTE_NONE

Now passes `quotechar` to csv's writer. Default is same as csv (`'"'`),
but sets to `None` with `quoting=csv.QUOTE_NONE`.
Merge pull request #4752 from jtratner/fix-to_csv_QUOTE_NONE-GH4328

BUG: Fix crash using to_csv with QUOTE_NONE