Adding util script to add & delete user

Adding scripts to quickly create user & delete user to test routes
Adding util scripts to ignore file
Adding new routes

* get group by id
* delete group by id
TODO : JSON wrapper for results
Merge branch 'correct-commits' into v2
Merge branch 'v2' of github.com:Linkur/linkur into v2
Adding JSON serializer

JSON serializer to convert lists, dictionaries, instances of models into
JSON object which will be used later by make_response as response for
HTTP calls

TODO one huge round of tests and documentation
Adding JSON response to routes

* Using jsonWrapper to serialize the result and send HTTP response
* Deleting unwanted methods in the model classes

TODO:
* test routes and reponses
* add comments