date was wrong; fixed (#1570)

Signed-off-by: Sloan, Adam <Adam_Sloan@comcast.com>

Author: asloan7

README.md

@@ -45,7 +45,7 @@ To learn more about Cortex, consult the following documents & talks:
 - Jun 2017 Prometheus London meetup talk; "Cortex: open-source, horizontally-scalable, distributed Prometheus" ([video][prometheus-london-2017-video])
 - Dec 2016 KubeCon talk; "Weave Cortex: Multi-tenant, horizontally scalable Prometheus as a Service" ([video][kubecon-2016-video], [slides][kubecon-2016-slides])
 - Aug 2016 PromCon talk; "Project Frankenstein: Multitenant, Scale-Out Prometheus": ([video][promcon-2016-video], [slides][promcon-2016-slides])
-- Jun 2018 design document; "[Project Frankenstein: A Multi Tenant, Scale Out Prometheus](http://goo.gl/prdUYV)"
+- Jun 2016 design document; "[Project Frankenstein: A Multi Tenant, Scale Out Prometheus](http://goo.gl/prdUYV)"
 
 [kubecon-cortex-intro]: https://kccnceu19.sched.com/event/MPhX/intro-cortex-tom-wilkie-grafana-labs-bryan-boreham-weaveworks
 [kubecon-cortex-intro-video]: https://www.youtube.com/watch?v=_7Wnta-3-W0