SNIMissingWarning on deploying to heroku

[josephgodwinkimani]

On deployment heroku builds it successfully and makes a HTTPS request , but the SNI (Subject Name Indication) extension to TLS is not available on python-2.7.4 This may cause the server to present an incorrect TLS certificate, which can cause validation failures. Thus I changed what was in runtime.txt to python-2.7.11 but I get Internal Server Error after clean deployment.

The flask-blog is using certifi, pyopenssl ndg-httpsclient pyasn1, urllib3[secure] and cryptography to enable HTTPS verification. I am lost what might be the problem?
requirements.txt
config.py.txt
Procfile.txt