bugfix: tests: renamed import because of changed filenames

Signed-off-by: Dominik Richter <dominik.richter@gmail.com>
Add data model and alembic migrations

Add Node and Pacakge data model classes
Use Alembic to migrate/upgrade the db structure
Add configuration classes
	Use sqlite for development purposes

Refactor project structure:
- Database code now in a seperate file
- Models live in ponyexpress.models
- manage.py in the root path for proper module imports
Add relations to the data model

Node has Packages, Packages are installed on Nodes. Add the
appropriate migrations for the data model.

Signed-off-by: Christoph Kassen <c.kassen@telekom.de>
Merge branch 'feature/database-models' of github.com:TelekomCloud/pony-express into feature/database-models

* 'feature/database-models' of github.com:TelekomCloud/pony-express:
  Add response after sucessful import
  Use correct datatype to access json data
  Add relations to the data model
  Add data model and alembic migrations

Conflicts:
	ponyexpress/api/v1/collector.py
Refactor for tests

Add tests for collector:
Some refactoring was required to work around some Flask problems.

Test files must be named test_* to be picked up by nose automatically.

Signed-off-by: Christoph Kassen <c.kassen@telekom.de>