Implement 'add vehicle' functionality.
Add preview div for editing vehicles
Implement and add tests for admin form view.
Implement editing of vehicles. No fully working yet due to string representation of numbers in VehicleService.
Fix tests.
Change VehicleService to use actual numbers instead of their String representation.
remove "posttest" script as E2E-tests are now done through protractor.
Provide purchase date in ISO format to not confuse browser/angular validation of "date" form fields.