Remove past events from calendar.

wiki/src/contribute/calendar.mdwn

 [[!meta title="Calendar"]]
 
-* 2014-06-08:
-  - Firefox 24.6.0 ESR sources are available.
-  - Package and upload Firefox 24.6.0 ESR.
-  - Tag 1.1 in Git.
-  - Start building and uploading 1.1 ISO/IUKs...
-
-* 2014-06-09:
-  - Finish building  by 12:00 (CEST)
-  - Start testing Tails 1.1 at 12:00 (CEST)...
-
-* 2014-06-10:
-  - ... and finish it by 12:00 (CEST) on the 10th.
-  - Officially release [Tails 1.1](https://labs.riseup.net/code/projects/tails/roadmap#Tails_1.1)
-
-* 2014-06-11 - [Tails contributors meeting](https://mailman.boum.org/pipermail/tails-dev/2014-May/005818.html)
-
 * 2014-07-05--2014-07-06 - Tails hackfest at
   [IRILL](http://www.irill.org/) (Paris, France)