Added basic slack action support

src/Nest.Watcher/Domain/Action/ActionType.cs

@@ -18,6 +18,8 @@ public enum ActionType
 		[EnumMember(Value = "logging")]
 		Logging,
 		[EnumMember(Value = "webhook")]
-		Webhook
-	}
+		Webhook,
+        [EnumMember(Value = "slack")]
+        Slack
+    }
 }

src/Nest.Watcher/Domain/Action/SlackAction.cs

@@ -0,0 +1,28 @@
+using System.Collections.Generic;
+using Nest.Resolvers.Converters;
+using Newtonsoft.Json;
+
+namespace Nest
+{
+    [JsonObject]
+    [JsonConverter(typeof(ReadAsTypeConverter<SlackAction>))]
+    public interface ISlackAction : IAction
+    {
+    }
+
+    public class SlackAction : Action, ISlackAction
+    {
+        public string Account { get; set; }
+        public Message Message { get; set; }
+    }
+
+    [JsonObject]
+    public class Message
+    {
+        [JsonProperty("to")]
+        public IList<string> To { get; set; }
+
+        [JsonProperty("text")]
+        public string Text { get; set; }
+    }
+}

src/Nest.Watcher/Nest.Watcher.csproj

@@ -56,6 +56,7 @@
     <Compile Include="Domain\ActionExecution\ExecutionResult.cs" />
     <Compile Include="Domain\Action\Action.cs" />
     <Compile Include="Domain\Action\ActionType.cs" />
+    <Compile Include="Domain\Action\SlackAction.cs" />
     <Compile Include="Domain\Condition\CompareCondition.cs" />
     <Compile Include="Domain\ActionExecution\ActionExecutionMode.cs" />
     <Compile Include="Domain\Enums\LogLevel.cs" />

src/Nest.Watcher/Serialization/ActionDictionaryConverter.cs

@@ -78,7 +78,9 @@ public override void WriteJson(JsonWriter writer, object value, JsonSerializer s
 					WriteActionEntry(kvp.Key, "webhook", kvp.Value, writer, serializer);
 				else if (kvp.Value is ILoggingAction)
 					WriteActionEntry(kvp.Key, "logging", kvp.Value, writer, serializer);
-				else
+                else if (kvp.Value is ISlackAction)
+                    WriteActionEntry(kvp.Key, "slack", kvp.Value, writer, serializer);
+                else
 					throw new ArgumentException("Unknown IAction type");
 			}
 			writer.WriteEndObject();

src/Tests/Nest.Watcher.Tests.Unit/Put/PutActionsJsonTests.cs

@@ -147,5 +147,43 @@ public void WebHook()
 			this.JsonEquals(expectedRequest, response);
 		}
 
-	}
+        [Test]
+        public void SlackAction()
+        {
+            var expectedRequest = new
+            {
+                actions = new
+                {
+                    slack = new
+                    {
+                        slack = new
+                        {
+                            account = "slackAccount",
+                            message = new 
+                            {
+                                to = new[] { "#general" },
+                                text = "Testing Slack Watcher Integration"
+                            }
+                        }
+                    }
+                }
+            };
+            var response = this.Client.PutWatch("some-watch", p => p
+                .Actions(a => a
+                    .Add("slack", new SlackAction
+                    {
+                        Account = "slackAccount",
+                        Message = new Message
+                        {
+                            Text = "Testing Slack Watcher Integration",
+                            To = new[] { "#general" }
+                        }
+                    })
+                )
+            );
+            this.JsonEquals(expectedRequest, response);
+        }
+
+
+    }
 }