cpanfile.snapshot should be rebuild

[smonff]

Hi,

After reading about towncrier in Perlweekly #388, I gave it a try and installed it in a clean environment with the recommended process.

Though, carton install --deployment failed.

I think it hasn't been updated after changes in cpanfile. I deleted the snapshot and did a carton install again and things went better. The snapshot should maybe be re-published this way. It can be related to other issues opened before, like #3 and #7.

Hope it helps.