Refactor the Balance Filter and add an integration test (#367)

Signed-off-by: Clement Escoffier <clement.escoffier@gmail.com>
Document the balance filter (#367)

Signed-off-by: Clement Escoffier <clement.escoffier@gmail.com>
When deploying the test bundle in blackbox test, we should wait for stability

Signed-off-by: Clement Escoffier <clement.escoffier@gmail.com>
Explicitly ask to deploy the test bundle in the CORSTIT tests

Signed-off-by: Clement Escoffier <clement.escoffier@gmail.com>
Add documentation to the CORS support (#367)

Signed-off-by: Clement Escoffier <clement.escoffier@gmail.com>