Since the latest iTunes update (28/02/2018) the step is failing to upload the binaries, with the error
ERROR: Could not start delivery: all transports failed diagnostics.
To fix it, I used an approach recommended on an issue open in the github repo of the same step. But, in my case, it cannot be done on fastfile, because I don’t use those. Given that the step is failling for all the builds, since yesterday, I updated the step.
Here is a PR with error description, and possible solution: https://github.com/bitrise-io/steps-deploy-to-itunesconnect-deliver/issues/30