scripts: Added tracking/clear.py script
scripts: Added tracking/generate.py script
tracking: Added pilot list to tracking views for multiple tracks
tracking: Load the clubs via joinedload instead of 1+n
Merge pull request #162 from Turbo87/tracking

Improved views for tracking multiple users
Removed obsolete download_xcsoar_tools.sh script

This has been replace with the `xcsoar` package
tests: Moved test to top folder

The tests are not part of the `skylines` module
flask: Removed unnecessary static_folder constructor parameter

We have the assets blueprint for that.
public: Moved to assets/static/
websetup: Moved bootstrapping code to tests.data
Merge pull request #164 from Turbo87/cleanup

Folder structure cleanup
alembic: Added `alembic` package to requirements
alembic: Created alembic environment
scripts: Added alembic table creation to initialise_database.py
Removed old migrations scripts from assets/SQL/
Added alembic upgrade to restart.sh
Merge pull request #165 from Turbo87/alembic

Use Alembic for database migrations
Moved OpenLayers config file into assets/static/ folder