Delete json-mode.el and install via package.el
Delete ace-jump-mode.el and install via package
Remove jinja2-mode.el and install via elpa

Also removed the key binding to enable jinja-mode in html buffers since
I didn't really use it
Add and load the pkg-tools.el mode
Add requirements.txt file

The 'pkg-tools-freeze' command freezes the list of installed emacs
packages to this file. It will be used for tracking installed files
hence forth
Enable rainbow-delimiters for clojure-mode