Update dropbox to 11.21.0

[pyup-bot]

This PR updates dropbox from 6.4.0 to 11.21.0.

Changelog

11.21.0

Release Notes:

* Automated Spec Update ([388](https://github.com/dropbox/dropbox-sdk-python/pull/388))

11.20.0

Release Notes:

* Automated Spec Update ([386](https://github.com/dropbox/dropbox-sdk-python/pull/386))

* Automated Spec Update ([383](https://github.com/dropbox/dropbox-sdk-python/pull/383))

11.19.0

* Automated Spec Update ([383](https://github.com/dropbox/dropbox-sdk-python/pull/383))

11.18.0

Release Notes:

* Automated Spec Update ([382](https://github.com/dropbox/dropbox-sdk-python/pull/382))

11.17.0

Release Notes:

* Automated Spec Update ([379](https://github.com/dropbox/dropbox-sdk-python/pull/379))

11.16.0

Release Notes: 

* Automated Spec Update ([378](https://github.com/dropbox/dropbox-sdk-python/pull/378)) 

* Add integration tests to the test suite ([377](https://github.com/dropbox/dropbox-sdk-python/pull/377))

11.15.0

Release Notes:

* Automated Spec Update ([376](https://github.com/dropbox/dropbox-sdk-python/pull/376))

11.14.0

Release Notes: 

* Add Support for Multi-Auth ([371](https://github.com/dropbox/dropbox-sdk-python/pull/371))

11.13.3

* Automated Spec Update ([373](https://github.com/dropbox/dropbox-sdk-python/pull/373))

11.13.2

Release Notes:

* Automated Spec Update ([372](https://github.com/dropbox/dropbox-sdk-python/pull/372))

11.13.1

Release Notes: 

* Automated Spec Update ([370](https://github.com/dropbox/dropbox-sdk-python/pull/370))

11.13.0

Release Notes: 

* Automated Spec Update ([368](https://github.com/dropbox/dropbox-sdk-python/pull/368))

11.12.0

Release Notes:

* Automated Spec Update ([366](https://github.com/dropbox/dropbox-sdk-python/pull/366))

11.11.0

Release Notes: 

* Automated Spec Update ([365](https://github.com/dropbox/dropbox-sdk-python/pull/365))

11.10.0

Release Notes: 

* Automated Spec Update ([362](https://github.com/dropbox/dropbox-sdk-python/pull/362))

11.9.0

Release Notes: 

* Automated Spec Update ([354](https://github.com/dropbox/dropbox-sdk-python/pull/354)) 

* Refresh access token when using a very old short-lived access token with unknown expiration ([352](https://github.com/dropbox/dropbox-sdk-python/pull/352))

11.8.0

Release Notes:

* Automated Spec Update ([351](https://github.com/dropbox/dropbox-sdk-python/pull/351))

11.7.0

Release Notes:

* Automated Spec Update ([344](https://github.com/dropbox/dropbox-sdk-python/pull/344))

* Bump actions/setup-python from v2.2.1 to v2.2.2 ([342](https://github.com/dropbox/dropbox-sdk-python/pull/342))

* Bump codecov/codecov-action from v1.2.1 to v1.3.2 ([339](https://github.com/dropbox/dropbox-sdk-python/pull/339))

* Update Release Notes Generator to Fetch Latest Tags ([341](https://github.com/dropbox/dropbox-sdk-python/pull/341))

11.6.0

Release Notes: 

* Automated Spec Update ([340](https://github.com/dropbox/dropbox-sdk-python/pull/340))

11.5.0

Release Notes: 

* Automated Spec Update ([337](https://github.com/dropbox/dropbox-sdk-python/pull/337))

11.4.1

Release Notes:

* Fix status classifier in setup.py ([334](https://github.com/dropbox/dropbox-sdk-python/pull/334))

* Fix setup.py dependencies by removing pull from requirements.txt ([333](https://github.com/dropbox/dropbox-sdk-python/pull/333))

11.4.0

Release Notes: 

* Move requirements.txt and test/requirements.txt as source of truth ([329](https://github.com/dropbox/dropbox-sdk-python/pull/329)) 

* Automated Spec Update ([330](https://github.com/dropbox/dropbox-sdk-python/pull/330)) 

* Update dropbox reference to link to the new name to fix documentation ([328](https://github.com/dropbox/dropbox-sdk-python/pull/328)) 

* Fix and update build step for Python2.7 ([326](https://github.com/dropbox/dropbox-sdk-python/pull/326)) 

* Fix DropboxOAuth2Flow Documentation Parameters ([325](https://github.com/dropbox/dropbox-sdk-python/pull/325)) 

* Automated Spec Update ([324](https://github.com/dropbox/dropbox-sdk-python/pull/324))

11.2.0

Release Notes:

* Automated Spec Update ([323](https://github.com/dropbox/dropbox-sdk-python/pull/323))

* Bump peter-evans/create-pull-request from v3.7.0 to v3.8.2 ([322](https://github.com/dropbox/dropbox-sdk-python/pull/322))

11.1.0

Release Notes:

* Bump peter-evans/create-pull-request from v3.5.1 to v3.7.0 ([318](https://github.com/dropbox/dropbox-sdk-python/pull/318))

* Automated Spec Update ([317](https://github.com/dropbox/dropbox-sdk-python/pull/317))

* Bump codecov/codecov-action from v1.0.15 to v1.2.1 ([315](https://github.com/dropbox/dropbox-sdk-python/pull/315))

* Bump actions/setup-python from v2.1.4 to v2.2.1 ([306](https://github.com/dropbox/dropbox-sdk-python/pull/306))

* Convert integration tests to use pytest instead of unittest ([313](https://github.com/dropbox/dropbox-sdk-python/pull/313))

* Add support for app authentication ([305](https://github.com/dropbox/dropbox-sdk-python/pull/305))

* Reorganize test directory ([312](https://github.com/dropbox/dropbox-sdk-python/pull/312))

* Fix CI matrix Python version ([311](https://github.com/dropbox/dropbox-sdk-python/pull/311))

11.0.0

Release Notes:

* Add stone to setup.py ([300](https://github.com/dropbox/dropbox-sdk-python/pull/300))

* Automated Spec Update ([296](https://github.com/dropbox/dropbox-sdk-python/pull/296))

* Fix links in release notes to be absolute ([287](https://github.com/dropbox/dropbox-sdk-python/pull/287))

* Bump peter-evans/create-pull-request from v3.4.1 to v3.5.1 ([297](https://github.com/dropbox/dropbox-sdk-python/pull/297))

* change update_version.sh to reflect the renaming of dropbox/dropbox.py to dropbox/dropbox_client.py ([294](https://github.com/dropbox/dropbox-sdk-python/pull/294))

* Regenerate client using Stone 3.2.0 ([291](https://github.com/dropbox/dropbox-sdk-python/pull/291))

* Bump codecov/codecov-action from v1.0.14 to v1.0.15 ([290](https://github.com/dropbox/dropbox-sdk-python/pull/290))

* remove auto generated stone_fixtures.py ([292](https://github.com/dropbox/dropbox-sdk-python/pull/292))

* Automated Spec Update ([288](https://github.com/dropbox/dropbox-sdk-python/pull/288))

10.10.0

* Automated Spec Update ([288]((https://github.com/dropbox/dropbox-sdk-python/pull//288)))

10.9.0

Release Notes:

* Automated Spec Update ([284](https://github.com/dropbox/dropbox-sdk-python/pull/284))

* Migrate references of master to main ([282](https://github.com/dropbox/dropbox-sdk-python/pull/282))

* Migrate primary branch to `main`

10.8.0

Release Notes:

* Automated Spec Update ([281](github.com/dropbox/dropbox-sdk-python/pull/281))

* Update dispatch on spec update workflow ([280](github.com/dropbox/dropbox-sdk-python/pull/280))

10.7.0

Release Notes:

* Fix default in getAuthenticationUrl to pass  if requested ([271](github.com/dropbox/dropbox-sdk-python/pull/271))

* Automated Spec Update  ([278](https://github.com/dropbox/dropbox-sdk-python/pull/278))

* Bump codecov/codecov-action from v1.0.13 to v1.0.14 ([276](github.com/dropbox/dropbox-sdk-python/pull/276))

* Bump actions/setup-python from v2.1.3 to v2.1.4 ([270](github.com/dropbox/dropbox-sdk-python/pull/270))

10.6.0

Release Notes:

* Automated Spec Update ([267](https://github.com/dropbox/dropbox-sdk-python/pull/267))

* Bump peter-evans/create-pull-request from v3.4.0 to v3.4.1 ([268](https://github.com/dropbox/dropbox-sdk-python/pull/268))

Links

• PyPI: https://pypi.org/project/dropbox
• Changelog: https://pyup.io/changelogs/dropbox/
• Homepage: http://www.dropbox.com/developers

[pyup-bot]

Closing this in favor of #817