Add integration tests for cloudflare and fastly. (#85)
Add integration tests for cloudflare and fastly. (#85)

Only checks that the systems build; this should be enough to catch the
breakages introduced in commit df66eb3 and fixed in commits 15f6d36 and
b814b6b, for instance.

A future commit will validate the signed exchanges they produce.
google/sxg-rs,google/sxg-rs,google/sxg-rs,google/sxg-rs,google/sxg-rs,google/sxg-rs