PLT-1527 Add a slash command to set yourself away (#3752)

* added handlers for slash commands

* added manual status persistance

* added tests

* removed extra debug output and comments

* rebase - fixing the PR

* making echo messages after slash commands ephemeral

api/command_statuses_test.go

@@ -0,0 +1,40 @@
+// Copyright (c) 2016 Mattermost, Inc. All Rights Reserved.
+// See License.txt for license information.
+
+package api
+
+import (
+	"testing"
+	"time"
+
+	"github.com/mattermost/platform/model"
+)
+
+func TestStatusCommands(t *testing.T) {
+	th := Setup().InitBasic()
+	commandAndTest(t, th, "away")
+	commandAndTest(t, th, "offline")
+	commandAndTest(t, th, "online")
+}
+
+func commandAndTest(t *testing.T, th *TestHelper, status string) {
+	Client := th.BasicClient
+	channel := th.BasicChannel
+	user := th.BasicUser
+
+	r1 := Client.Must(Client.Command(channel.Id, "/"+status, false)).Data.(*model.CommandResponse)
+	if r1 == nil {
+		t.Fatal("Command failed to execute")
+	}
+
+	time.Sleep(300 * time.Millisecond)
+
+	statuses := Client.Must(Client.GetStatuses()).Data.(map[string]string)
+
+	if status == "offline" {
+		status = ""
+	}
+	if statuses[user.Id] != status {
+		t.Fatal("Error setting status " + status)
+	}
+}