fix pre-formed entry upload (sigstore#392)

Signed-off-by: Bob Callaway <bob.callaway@gmail.com>

add set signature and verification on get (sigstore#333)

Signed-off-by: Asra Ali <asraa@google.com>

Merge pull request sigstore#195 from dlorenc/warn

Add some text explaining the lack of SLOs on our production instance.

Merge pull request sigstore#98 from dlorenc/moree2e

Add an e2e test that uses verify.