Add chat.postEphemeral to Node SDK

lib/clients/web/facets/chat.js

@@ -4,6 +4,7 @@
  * This provides functions to call:
  *   - delete: {@link https://api.slack.com/methods/chat.delete|chat.delete}
  *   - meMessage: {@link https://api.slack.com/methods/chat.meMessage|chat.meMessage}
+ *   - postEphemeral: {@link https://api.slack.com/methods/chat.postEphemeral|chat.postEphemeral}
  *   - postMessage: {@link https://api.slack.com/methods/chat.postMessage|chat.postMessage}
  *   - update: {@link https://api.slack.com/methods/chat.update|chat.update}
  *
@@ -56,6 +57,36 @@ ChatFacet.prototype.meMessage = function meMessage(channel, text, optCb) {
 };
 
 
+/**
+ * Sends an ephemeral message to a user in a channel.
+ * @see {@link https://api.slack.com/methods/chat.postEphemeral|chat.postEphemeral}
+ *
+ * @param {?} channel - Channel, private group, or IM channel to send message to. Can be an
+ *   encoded ID, or a name. See [below](#channels) for more details.
+ * @param {?} text - Text of the message to send. See below for an explanation of
+ *   [formatting](#formatting). This field is usually required, unless you're providing only
+ *   `attachments` instead.
+* @param {?} user - `id` of the user who will receive the ephemeral message.
+ *   The user should be in the channel specified by the `channel` argument.
+ * @param {Object=} opts
+ * @param {?} opts.parse - Change how messages are treated. Defaults to `none`. See
+ *   [below](#formatting).
+ * @param {?} opts.link_names - Find and link channel names and usernames.
+ * @param {?} opts.attachments - Structured message attachments.
+ * @param {?} opts.as_user - Pass true to post the message as the authed user, instead of as a
+ *   bot. Defaults to false. See [authorship](#authorship) below.
+ * @param {function=} optCb Optional callback, if not using promises.
+ */
+ChatFacet.prototype.postEphemeral = function postEphemeral(channel, text, user, opts, optCb) {
+  var requiredArgs = {
+    channel: channel,
+    text: text,
+    user: user
+  };
+
+  return this.makeAPICall('chat.postEphemeral', requiredArgs, opts, optCb);
+};
+
 /**
  * Sends a message to a channel.
  * @see {@link https://api.slack.com/methods/chat.postMessage|chat.postMessage}