Introduce QUOTE_NONNUMERIC on WriteQuoteMode

In some case, it may be better not to quote the numeric type field. (e.g. In case of opening written CSV with Microsoft Excel)

Below CSV is QUOTE_NONNUMERIC option's example.
```
"a","b",1
2.0,"e","f"
```

See also
https://github.com/tototoshi/scala-csv/blob/master/src/main/scala/com/github/tototoshi/csv/CSVWriter.scala#L58