chore(deps): update dependency certifi to v2020.6.20 (#5)

Co-authored-by: Renovate Bot <bot@renovateapp.com>

Author: renovate[bot]

requirements.txt

@@ -1,4 +1,4 @@
-certifi==2020.4.5.1
+certifi==2020.6.20
 chardet==3.0.4
 idna==2.10
 requests==2.24.0