Disabling versionKey when not used

Only for array data, says the doc
Using ID everywhere

Hiding the _id internal mongoose ID for users and views.
Fixing bugs with PUT query with custom criteria
Moar tests

Applications Rest API tests
Test for Applications & Targets Rest API
Sample data for tests
Add tests for devices REST API
.gitignore
Fixing PUT

Thank you tests
Adding pm2
Merge branch 'Unit-tests'
Added refactoring test files