Exportcsvtoinflux

Fix -v not working issue

Fix the chardet issue in setup

1. Support the Influxdb2.x
2. Could be able to write the duplicate points by enable: `--unique True`
3. Could be able to parse the csv files with different encodings by auto detecting. Or you could use the comand to specify the charset: `--csv_charset utf-8-sig`
4. Several bug fixes

Note: To make the 0.2.0 working, install `pip install chardet`

First, really appreciate 7yl4r's help for the pull request.

Here are the fix details:
1. Cannot handle times before posix 1000000000, which is already fixed by: 7yl4r's pull request - https://github.com/Bugazelle/export-csv-to-influx/pull/33
2. empty columns throws cryptic error: https://github.com/Bugazelle/export-csv-to-influx/issues/34
3. force value to int or float fail messages are backwards: https://github.com/Bugazelle/export-csv-to-influx/issues/36

Feat: Support --force_float_columns and --force_int_columns

1. Feat: _influx.csv file could be ignored
2. Fix: Fix process issue when csv cell value empty