Add release_counter to Repo API (#9214)

models/repo.go

 		Watchers:                  repo.NumWatches,
 		OpenIssues:                repo.NumOpenIssues,
 		OpenPulls:                 repo.NumOpenPulls,
+		Releases:                  repo.NumReleases,
 		DefaultBranch:             repo.DefaultBranch,
 		Created:                   repo.CreatedUnix.AsTime(),
 		Updated:                   repo.UpdatedUnix.AsTime(),

modules/structs/repo.go

 	Watchers      int         `json:"watchers_count"`
 	OpenIssues    int         `json:"open_issues_count"`
 	OpenPulls     int         `json:"open_pr_counter"`
+	Releases      int         `json:"release_counter"`
 	DefaultBranch string      `json:"default_branch"`
 	Archived      bool        `json:"archived"`
 	// swagger:strfmt date-time

templates/swagger/v1_json.tmpl

           "type": "boolean",
           "x-go-name": "Private"
         },
+        "release_counter": {
+          "type": "integer",
+          "format": "int64",
+          "x-go-name": "Releases"
+        },
         "size": {
           "type": "integer",
           "format": "int64",