refactor! remove pkg directory (#145)

* refactor!: remove pkg directory

* chore: include breaking changes in draft

types.go

@@ -0,0 +1,37 @@
+package attest
+
+import (
+	"fmt"
+
+	"github.com/docker/attest/policy"
+	v1 "github.com/google/go-containerregistry/pkg/v1"
+	intoto "github.com/in-toto/in-toto-golang/in_toto"
+)
+
+type Outcome string
+
+const (
+	OutcomeSuccess  Outcome = "success"
+	OutcomeFailure  Outcome = "failure"
+	OutcomeNoPolicy Outcome = "no_policy"
+)
+
+func (o Outcome) StringForVSA() (string, error) {
+	switch o {
+	case OutcomeSuccess:
+		return "PASSED", nil
+	case OutcomeFailure:
+		return "FAILED", nil
+	default:
+		return "", fmt.Errorf("unknown outcome: %s", o)
+	}
+}
+
+type VerificationResult struct {
+	Outcome           Outcome
+	Policy            *policy.Policy
+	Input             *policy.Input
+	VSA               *intoto.Statement
+	Violations        []policy.Violation
+	SubjectDescriptor *v1.Descriptor
+}