Update requests to 2.22.0

[pyup-bot]

This PR updates requests from 2.21.0 to 2.22.0.

Changelog

2.22.0

-------------------

**Dependencies**

- Requests now supports urllib3 v1.25.2.
(note: 1.25.0 and 1.25.1 are incompatible)

**Deprecations**

- Requests has officially stopped support for Python 3.4.

Links

• PyPI: https://pypi.org/project/requests
• Changelog: https://pyup.io/changelogs/requests/
• Homepage: http://python-requests.org

[codecov]

Codecov Report

Merging #1006 into master will not change coverage.
The diff coverage is n/a.

@@          Coverage Diff           @@
##           master   #1006   +/-   ##
======================================
  Coverage     100%    100%           
======================================
  Files           9       9           
  Lines         422     422           
  Branches       10      10           
======================================
  Hits          422     422

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 12c589a...55f5a90. Read the comment docs.