update to version v2.11.1
* Update urllib3 to 1.16
* Close and then release the connection
* Added tests for should_bypass_proxies function
* Update documentation of Session.max_redirects
* Document bunch of return types
* Update HISTORY.rst
* Cleaning up comment on JSON encoding to be more strictly relevant.
* Oh yeah, we updated urllib3 too.
* Fixing test; it was accomplishing the right thing, but doing it in the wrong way.
* compensate for lack of taste
* Use xfail marker for a test expected to fail without Internet connection
* in python3.x not have StringIO
* Spelling fixes
* adding in slice_length fix and test for chunk_size=None (#3370)
* Support responses like `HTTP/1.1 404 Unicode chars` (#3385)
* Document header ordering. (#3295)
* Add section on SOCKS proxies.
* Update list of supported Python versions in todo.rst
* removing Content-Type and Transfer-Encoding headers on redirect
* check and test for headers containing return characters or leading whitespace
* Clarify Python versions supported by requests
* Allow graceful interruption of testserver.Server
* reverting 3362
* fixed date formatting
* Make BaseAdapter describe the mandatory adapter interface (#3216)
* Note how HTTPErrors are raised
* Removing charset from JSON content type; tightening requirements on .encode()
* Add 'all' proxy selection to select_proxy
* Fix TypeError when get json-encoded content of a response