auth: Remove "shared" aka "global" secrets.

server/auth/authtest/db.go

Index: server/auth/authtest/db.go
diff --git a/server/auth/authtest/db.go b/server/auth/authtest/db.go
index 9a757e41422b91bb06de90b99d2057b05b98ddfa..697ebf972a7f6aec44fcb2590b0a00591bd9e791 100644
--- a/server/auth/authtest/db.go
+++ b/server/auth/authtest/db.go
@@ -9,8 +9,6 @@ import (
 
 	"golang.org/x/net/context"
 
-	"github.com/luci/luci-go/server/secrets"
-
 	"github.com/luci/luci-go/server/auth"
 	"github.com/luci/luci-go/server/auth/authdb"
 	"github.com/luci/luci-go/server/auth/identity"
@@ -56,11 +54,6 @@ func (db FakeDB) IsAllowedOAuthClientID(c context.Context, email, clientID strin
 	panic("FakeDB.IsAllowedOAuthClientID must not be called")
 }
 
-// SharedSecrets is part of authdb.DB interface. Panics.
-func (db FakeDB) SharedSecrets(c context.Context) (secrets.Store, error) {
-	panic("FakeDB.SharedSecrets must not be called")
-}
-
 // GetCertificates is part of authdb.DB interface. Panics.
 func (db FakeDB) GetCertificates(c context.Context, id identity.Identity) (*signing.PublicCertificates, error) {
 	panic("FakeDB.GetCertificates must not be called")