fix: fix various linting errors

cmd/duffle/install_test.go

@@ -6,9 +6,9 @@ import (
 	"path/filepath"
 	"testing"
 
-	"github.com/deis/duffle/pkg/bundle"
 	"github.com/stretchr/testify/assert"
 
+	"github.com/deis/duffle/pkg/bundle"
 	"github.com/deis/duffle/pkg/duffle/home"
 )
 

pkg/bundle/parameters_test.go

@@ -352,7 +352,7 @@ func TestConvertValue(t *testing.T) {
 	is.NoError(err)
 	is.Equal(123, out.(int))
 
-	out, err = pd.ConvertValue("onetwothree")
+	_, err = pd.ConvertValue("onetwothree")
 	is.Error(err)
 }
 

pkg/signature/keys.go

@@ -83,10 +83,6 @@ func (k *Key) findPrivateKey() (*packet.PrivateKey, error) {
 	return nil, errors.New("no signing key found")
 }
 
-func canSign(k *openpgp.Key) bool {
-	return k.SelfSignature.FlagSign
-}
-
 // KeyRing represents a collection of keys as specified by OpenPGP
 type KeyRing struct {
 	entities          openpgp.EntityList

pkg/signature/signature_test.go

@@ -53,6 +53,7 @@ func TestSigner_Attest(t *testing.T) {
 	// Sign the bundle twice and make sure the sigs are the same.
 	s := NewSigner(k)
 	sig, err := s.Clearsign(b)
+	is.NoError(err)
 	attestation, err := s.Attest(sig)
 	is.NoError(err)
 	is.Contains(string(sig), string(attestation))

pkg/signature/verifier.go

@@ -4,9 +4,10 @@ import (
 	"bytes"
 	"encoding/json"
 
-	"github.com/deis/duffle/pkg/bundle"
 	"golang.org/x/crypto/openpgp"
 	"golang.org/x/crypto/openpgp/clearsign"
+
+	"github.com/deis/duffle/pkg/bundle"
 )
 
 // Verifier provides tools to verify a signed bundle.