Add a small note about requests-toolbelt
Add missing sled

Thanks @kevinburke
Update changelog for 2.2.1.
Update urllib3 to 9346c5c
Merge pull request #1876 from dstufft/update-urllib3

Update urllib3 to 9346c5c
v2.2.1
Merge pull request #1870 from sigmavirus24/add-toolbelt-to-docs

Add a small note about requests-toolbelt
NOTICE update
s/soley/solely
Merge pull request #1881 from kevinburke/typo

s/soley/solely
Added info about posted files headers
Merge pull request #1886 from meteozond/patch-1

Added info about posted files headers
test pyopenssl redirect (unit test for #1887)
on redirect pass URL as bytes. Fixes: #1887
Merge pull request #1888 from longaccess/handle301

Fix for 301 redirect and latest PyOpenSSL.
Move creation of attributes to RequestException

Pass request objects in HTTPAdapter
Avoid having to fix tests
Explicitly check for None
Repopulate ~/.netrc auth.
Avoid breaking crappy distribution methods.