Let the Tag deletion actually delete

Managers/TagManager.cs

@@ -17,7 +17,7 @@ namespace HabitSharp.Managers {
         public Result<Object> Delete(Tag t) => this.Delete(t.Id);
         public Result<Object> Delete(Guid id) => this.Delete(id.ToString());
         public Result<Object> Delete(string id) {
-            var req = new RestRequest("tags/{tagId}");
+            var req = new RestRequest("tags/{tagId}", Method.DELETE);
             req.AddUrlSegment("tagId", id);
             return this.Client.Execute<Result<Object>>(req);
         }