Log Message:
py-zipstream: update to version 1.1.8

Changes made after forking v1.1.4:

v1.1.5 (2019-03-18)

 * Support Zip64 when compressing iterables and strings \ 
(https://github.com/allanlei/python-zipstream/pull/25)

v1.1.6 (2019-06-06)

 * Add partial flushing of ZipStreams \ 
(https://github.com/arjan-s/python-zipstream/pull/1)

v1.1.7 (2019-10-22)

 * Stream data in the order it was received \ 
(https://github.com/arjan-s/python-zipstream/pull/4)

v1.1.8 (2020-09-14)

 * New datetime parameter in write_iter \ 
(https://github.com/arjan-s/python-zipstream/pull/8)