add finder app
add models to store puzzle vector
add pypuzzle as a dependency
add code to search using puzzle vector
store puzzle vector when an image is imported
add celery as a depencency, and add celery configs
use celery to create puzzle vector after saving images
use MySQL instead of SQLite for development, because sometimes database-locked error is raised when importing images
add Vagrantfile to construct a VM that runs MySQL and Redis servers for development
add tests