Update faas-provider

Signed-off-by: Alex Ellis (OpenFaaS Ltd) <alexellis2@gmail.com>

Update dependencies and add notice about JetStream

We have done a lot of R&D to bring JetStream to customers,
it's stable, and being used widely in production. Enjoy.

Signed-off-by: Alex Ellis (OpenFaaS Ltd) <alexellis2@gmail.com>

Update README.md

Signed-off-by: Alex Ellis <alexellis2@gmail.com>

Update internal dependencies

Signed-off-by: Alex Ellis (OpenFaaS Ltd) <alexellis2@gmail.com>