Influx-client

- Adds support for Python 2.7

Fixed crash when importing Influx data where a `tag` wasn't present in `fields`

* add a `drop_measurement` method to the client
* fix style issues related to the newest flake8 update that were causing the Docker build to fail

- `show_tags()` and `show_fields()`

- Adds `timeout=` option to `InfluxDB()` class

- Adds `desc=` option to `select_where()`