Bump cffi from 1.14.5 to 1.14.6 (#1406)

Bumps [cffi](http://cffi.readthedocs.org) from 1.14.5 to 1.14.6.

---
updated-dependencies:
- dependency-name: cffi
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <support@github.com>

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

requirements.txt

@@ -4,7 +4,7 @@ boto3==1.17.105
 botocore==1.20.109
 canonicaljson-rs==0.3.0
 certifi==2021.5.30
-cffi==1.14.5
+cffi==1.14.6
 chardet==4.0.0
 colander==1.8.3
 colorama==0.4.4