tests: lots of small asjustement

pkg/policy/policytest/policy.go

@@ -1,20 +0,0 @@
-// Package policytest provides values and functions that are useful when
-// testing code that relies on Policies.
-package policytest
-
-import (
-	"testing"
-
-	"github.com/stretchr/testify/require"
-	"github.com/ucan-wg/go-ucan/pkg/policy"
-)
-
-// EmptyPolicy provides a policy with no statements for testing purposes.
-func EmptyPolicy(t *testing.T) policy.Policy {
-	t.Helper()
-
-	pol, err := policy.FromDagJson("[]")
-	require.NoError(t, err)
-
-	return pol
-}