Add meta endpoint

HabiticaApi.cs

@@ -1,4 +1,5 @@
 using System;
+using System.Collections.Generic;
 using RestSharp;
 using HabitSharp.Managers;
 
@@ -28,5 +29,11 @@ namespace HabitSharp
                 response.ErrorException);
             return response.Data;
         }
+
+        public Result<Dictionary<string, string>> GetModelPaths(string ModelName) {
+            var req = new RestRequest("models/{model}/paths");
+            req.AddUrlSegment("model", ModelName);
+            return this.Execute<Result<Dictionary<string, string>>>(req);
+        }
     }
 }

Tag.cs

@@ -2,6 +2,7 @@ using System;
 
 namespace HabitSharp {
     public class Tag {
+        public const string ModelName = "tag";
         public Guid Id { get; set; }
         public string Name { get; set; }
         public bool Challenge { get; set; }