bump gotest.tools v3.0.1 for compatibility with Go 1.14

full diff: https://github.com/gotestyourself/gotest.tools/compare/v2.3.0...v3.0.1

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

cli-plugins/manager/candidate_test.go

@@ -7,8 +7,8 @@ import (
 	"testing"
 
 	"github.com/spf13/cobra"
-	"gotest.tools/assert"
-	"gotest.tools/assert/cmp"
+	"gotest.tools/v3/assert"
+	"gotest.tools/v3/assert/cmp"
 )
 
 type fakeCandidate struct {

cli-plugins/manager/error_test.go

@@ -6,7 +6,7 @@ import (
 
 	"github.com/pkg/errors"
 	"gopkg.in/yaml.v2"
-	"gotest.tools/assert"
+	"gotest.tools/v3/assert"
 )
 
 func TestPluginError(t *testing.T) {

cli-plugins/manager/manager_test.go

@@ -8,8 +8,8 @@ import (
 	"github.com/docker/cli/cli/config/configfile"
 	"github.com/docker/cli/internal/test"
 	"github.com/spf13/cobra"
-	"gotest.tools/assert"
-	"gotest.tools/fs"
+	"gotest.tools/v3/assert"
+	"gotest.tools/v3/fs"
 )
 
 func TestListPluginCandidates(t *testing.T) {