Bump cffi from 1.14.0 to 1.14.1

Bumps [cffi](https://bitbucket.org/cffi/release-doc) from 1.14.0 to 1.14.1.
- [Commits](https://bitbucket.org/cffi/release-doc/commits)

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

Author: dependabot-preview[bot]

requirements.txt

@@ -1,5 +1,5 @@
 bitarray-hardbyte==1.2.2
-cffi==1.14.0
+cffi==1.14.1
 clkhash==0.15.2
 Cython==0.29.21
 hypothesis==5.20.3