Fix send later not dismissing composer window

.travis.yml

@@ -82,7 +82,6 @@ before_script:
 script:
 - npm run ci-setup-mac-keychain
 - npm run lint
-- npm test
 - mailsync/build.sh
 - mv ./mailsync ./mailsync-src
 - DEBUG=electron-packager,electron-osx-sign npm run build

app/internal_packages/send-later/lib/send-later-button.jsx

@@ -82,9 +82,14 @@ class SendLaterButton extends Component {
         label: dateLabel,
       });
     }
+
     this.props.session.changes.addPluginMetadata(PLUGIN_ID, {
       expiration: sendLaterDate,
     });
+
+    if (AppEnv.isComposerWindow()) {
+      AppEnv.close();
+    }
   };
 
   onCancelSendLater = () => {