bump version to 0.4.0

The `replicate` package on PyPI used to be a different project (keepsake) with several releases. This big version bump skips over those old releases. After this we can start following Semantic Versioning

Signed-off-by: Zeke Sikelianos <zeke@sikelianos.com>

0.0.1a16

Signed-off-by: Ben Firshman <ben@firshman.co.uk>

bump version to 0.0.1a10

Signed-off-by: Zeke Sikelianos <zeke@sikelianos.com>

0.0.1a8

Signed-off-by: Ben Firshman <ben@firshman.co.uk>