have one file per scenario

[sishtiaq]

Why not have one history file per scenario (fstar, mitls, etc), rather than a file per run? Currently, there's lots of one-history-point files. Doing a comparison could be a matter of doing a git diff of the file's history, rather than a diff of different files.
The number of files will just grow: github's web UI already refuses to display >100.

[msprotz]

See also: project-everest/everest-ci#22

This means that notifications would have to change the URL to the logs -- also, I'm wondering what would happens with usernames, branches, etc.