release: tag version 2.1.1 for logging fix

Change-Id: I5f23d27db950e9d778787beaff5f0be132caa1d5

2.1.0

Changelog (since 2.0.0)
* T188193 (2018-07-23 10:53:54) Changed base namespace to MediaWiki\Extension
* T198928 (2018-07-14 22:06:29) Trust generated session id on new request
* T191730 (2018-07-14 22:06:29) Trust generated session id on new request
* T188195 (2018-03-27 22:24:34) Fully embrace associative arrays
* T171190 (2018-03-19 22:41:39) More distinctive cookie prefix
* T185281 (2018-03-17 14:12:06) Improved handling of special page 'CreateAccount'
* T185391 (2018-03-16 21:24:42) Firing hook 'UserLoggedIn'

2.0.1

Changelog
* T185391 (2018-03-16 21:24:42) Firing hook 'UserLoggedIn'

2.0.0

Changelog
* T188188 (2018-02-27 21:52:16): Support distribution via Composer and Packagist
* T185377 (2018-02-24 00:06:56): Fixed missing logout link text
* T183858 (2018-01-03 19:03:39): Use SPDX 3.0 license identifier
* T167615 (2017-06-12 02:44:47): Title::newFromText() can and does return null
* T165540 (2017-06-07 12:39:33): Add CODE_OF_CONDUCT.md
* T110292 (2017-04-16 20:08:37): Bug T110292 - Update Auth_remoteuser to use AuthManager