Upgrade dependencies for security

[zerothabhishek]

Ref: https://requires.io/github/pythonindia/junction/requirements/?branch=master

Many libraries in requirements.txt are using old, insecure versions. They must be updated to the latest secure versions.

This also requires a Django upgrade.
Related Issue: 514

[pradyunsg]

pillow seems to be unused.

[ananyo2012]

3 more dependencies need update - handlebars, extend and sshpk as pointed out by GitHub @dependabot

[gutsytechster]

Won't @dependabot create a PR if a security issue be found? Do we explicitly need to update some dependency?