remove more unused types

Signed-off-by: Kingdon Barrett <kingdon@weave.works>

pkg/checkpoint/types.go

@@ -5,25 +5,6 @@ import (
 	"time"
 )
 
-type checkAlert struct {
-	ID      int
-	Date    int
-	Message string
-	URL     string
-	Level   string
-}
-
-type checkResponse struct {
-	Product             string
-	CurrentVersion      string `json:"current_version"`
-	CurrentReleaseDate  int    `json:"current_release_date"`
-	CurrentDownloadURL  string `json:"current_download_url"`
-	CurrentChangelogURL string `json:"current_changelog_url"`
-	ProjectWebsite      string `json:"project_website"`
-	Outdated            bool   `json:"outdated"`
-	Alerts              []*checkAlert
-}
-
 type flag struct {
 	Key   string
 	Value string