maint: clean up some errors

pkg/cmd/gist/delete/delete.go

@@ -1,7 +1,7 @@
 package delete
 
 import (
-	"fmt"
+	"errors"
 	"net/http"
 	"strings"
 
@@ -80,7 +80,7 @@ func deleteRun(opts *DeleteOptions) error {
 	}
 
 	if username != gist.Owner.Login {
-		return fmt.Errorf("You do not own this gist.")
+		return errors.New("you do not own this gist")
 	}
 
 	err = deleteGist(apiClient, host, gistID)

pkg/cmd/gist/delete/delete_test.go

@@ -82,7 +82,7 @@ func Test_deleteRun(t *testing.T) {
 				Owner: &shared.GistOwner{Login: "octocat2"},
 			},
 			wantErr:    true,
-			wantStderr: "You do not own this gist.",
+			wantStderr: "you do not own this gist",
 		}, {
 			name: "successfully delete",
 			gist: &shared.Gist{

pkg/cmd/gist/edit/edit.go

@@ -126,7 +126,7 @@ func editRun(opts *EditOptions) error {
 	}
 
 	if username != gist.Owner.Login {
-		return fmt.Errorf("You do not own this gist.")
+		return errors.New("you do not own this gist")
 	}
 
 	shouldUpdate := false

pkg/cmd/gist/edit/edit_test.go

@@ -254,7 +254,7 @@ func Test_editRun(t *testing.T) {
 				},
 				Owner: &shared.GistOwner{Login: "octocat2"},
 			},
-			wantErr: "You do not own this gist.",
+			wantErr: "you do not own this gist",
 		},
 		{
 			name: "add file to existing gist",