Influxdb

Added
- Finally add a CHANGELOG.md to communicate breaking changes (598)
- Test multiple versions of InfluxDB in travis
- Add SHARD DURATION parameter to retention policy create/alter
Changed
- Update POST/GET requests to follow verb guidelines from InfluxDB documentation
- Update test suite to support InfluxDB v1.3.9, v1.4.2, and v1.5.4
- Fix performance degradation when removing NaN values via line protocol (592)
Removed
- Dropped support for Python3.4

Added
- Connect to InfluxDB path running on server (556 thx gladhorn)
- Escape measurement names in DataFrameClient (542 thx tzonghao)
- Escape tags that end with a backslash (537 thx vaniakov)
- Add back mistakenly-dropped database parameter (540)
- Add PyPI status to README.md
Changed
- Fix bad session mount scheme (571 thx vaniakov)
- Fixed issue with DataFrameClient calling to_datetime function (593 thx dragoshenron)
- Escape columns in DataFrameClient for line protocol (584 thx dmuiruri)
- Convert DataFrameClient times from int to np.int64 (495 thx patrickhoebeke)
- Updated pandas tutorial (547 thx techaddicted)
- Explicitly set numpy version for tox (563)
Removed
- Removed UDP precision restrictions on timestamp (557 thx mdhausman)

Added
- Add pool size parameter to client constructor (534 thx vaniakov)
- Add ping method to client for checking connectivity (409 thx pmenglund)
- Add retry logic & exponential backoff when a connection fails (508)
- Declare which setuptools version is required in PyPy env
- Functions for drop_measurement and get_list_measurements in InfluxDBClient (402 thx Vic020)
- Allow single string as data argument in write (492 thx baftek)
- Support chunked queries in DataFrameClient (439 thx gusutabopb)
- Add close method to InfluxDBClient (465 thx Linux-oiD)
- PEP257 linting & code compliance (473)
Changed
- Fix broken tags filtering on a ResultSet (511)
- Improve retry codepath for connecting to InfluxDB (536 thx swails)
- Clean up imports using six instead of sys.version (536 thx swails)
- Replace references to dataframe.ix with dataframe.iloc (528)
- Improve performance of tag processing when converting DataFrameClient to line protocol (503 thx tzonghao)
- Typo in Content-Type header (513 thx milancermak)
- Clean up README.md formatting
- Catch TypeError when casting to float to return False with objects (475 thx BenHewins)
- Improve efficiency of tag appending in DataFrameClient when converting to line protocol (486 thx maxdolle)
Removed
- Drop requirement for all fields in SeriesHelper (518 thx spott)
- use_udp and udp_port are now private properties in InfluxDBClient

Added
Changed
Removed

Added
Changed
Removed

Others
1. [472](https://github.com/influxdata/influxdb-client-python/pull/472): Drop supports for Python 3.6
1. [495](https://github.com/influxdata/influxdb-client-python/pull/495): Add warning for measurement name starts with `#`

Documentation
1. [397](https://github.com/influxdata/influxdb-client-python/pull/397): Add an example: How to use RxPY to prepare batches by maximum bytes count
1. [269](https://github.com/influxdata/influxdb-client-python/pull/269): Add new example: How to check connection credentials