Update README.md

Added tests for ER → JSON and JSON → Cypher (#5)

* Ran 'npm audit fix'

* Updated a few dependencies

* Updated a few dependencies #2

* Removed unnecessary dependecy 'ejs'

* Updated a few dependencies

* Updated a few dependencies

* Updated README

* Updated remaining dependencies

* Updated one more dependency

* Added 'About' section to README

* Updated screenshot

* Adding Jest to the application

* Using JSON Jest config instead of js

* First test OK

* Second test OK

* Re-generated package-lock.json

Composite attributes working again

Fixed a few labels

Fixed hard-coded value in union trigger

Removed variable schema

Implemented weak entities

N-ary relationships behave just like associative entities

Fixed triggers with duplicated names

Strict mode now correctly handles n-ary relationships