Update the HISTORY for v1.2
Add correct defaults in Session.send()

Resolves #1258

Also fixed the tests to reflect the necessary changes.
This should take care of #1266

We were sending 'None' as the Content-Length on requests where the body was a
generator. This commit should prevent that entirely.
Finally resolve #1084

Send body on redirect when POSTing or PUTing.
Restore Session.request docstring

Resolves #1251
Fix the tests and unseparate comments from code

See the comments on the previous few commits on GitHub.
update vendored urllib3
Use session defaults instead of arbitrary ones
Merge pull request #1270 from makto/add_attr

add 'max_redirects' to Session's __attrs__
Merge pull request #1267 from sigmavirus24/master

One last pull request before 1.2 ideally
fix syntax error
Merge pull request #1268 from t-8ch/update_urllib3

update vendored urllib3
v1.2.0
Merge remote-tracking branch 'origin/master'
is should not be used for comparing numbers
Fixed typos
fix tiny typo in HISTORY.rst
Merge pull request #1276 from alex/patch-1

is should not be used for comparing numbers
Merge pull request #1277 from pborreli/typos

Fixed typos
Merge pull request #1278 from t-8ch/patch-1

fix tiny typo in HISTORY.rst