Add melandory to the components/invalidation OWNERS

Bug: 880056, 801985
Change-Id: I0606bb84518b35a8d965e6bb2fb44bb6fcee5620
Reviewed-on: https://chromium-review.googlesource.com/c/1307435Reviewed-by: Pavel Yatsuk <pavely@chromium.org>
Commit-Queue: Tatiana Gornak <melandory@chromium.org>
Cr-Commit-Position: refs/heads/master@{#604213}

components/invalidation/OWNERS

 dcheng@chromium.org
 nyquist@chromium.org
 pavely@chromium.org
+melandory@chromium.org
 
 # COMPONENT: Services>Invalidation