Fix #1275: add aliases to cluster state response

Author: gmarz

src/Nest/Domain/State/ClusterState.cs

@@ -90,7 +90,7 @@ public class MetadataIndexState
 		[JsonConverter(typeof(DictionaryKeysAreNotPropertyNamesJsonConverter))]
 		public Dictionary<string, ObjectMapping> Mappings { get; internal set; }
 
-		//[JsonProperty("aliases")]
-		//public ?? Aliases { get; internal set; }
+		[JsonProperty("aliases")]
+		public IEnumerable<string> Aliases { get; internal set; }
 	}
 }

src/Tests/Nest.Tests.Integration/Cluster/StateTests.cs

@@ -22,6 +22,7 @@ public void SimpleState()
 				if (!index.Key.StartsWith("nest"))
 					continue;
 				Assert.NotNull(index.Value.Mappings);
+				Assert.NotNull(index.Value.Aliases);
 				Assert.True(index.Value.Mappings.Count > 0, "{0}" , index.Key);
 			}