Update subscriberIdsToNotify to send unique emails
Update subscriberIdsToNotify to send unique emails

Added .uniq() for subscribersIdsToNotify in the Categories section to prevent a user from receiving multiple emails if he/she is subscribed to multiple categories.
nathanmelenbrink/theRecord,julienlapointe/telescope-nova-social-news,SachaG/Zensroom,bengott/Telescope,SachaG/Gamba,VulcanJS/Vulcan,jonmc12/heypsycho,rtluu/immersive,Discordius/Lesswrong2,dominictracey/Telescope,VulcanJS/Vulcan,Discordius/Telescope,basemm911/questionsociety,Discordius/Lesswrong2,Discordius/Lesswrong2,SachaG/Gamba,bshenk/projectIterate,nathanmelenbrink/theRecord,JstnEdr/Telescope,Discordius/Telescope,Air2air/Telescope,HelloMeets/HelloMakers,bshenk/projectIterate,dominictracey/Telescope,TodoTemplates/Telescope,basemm911/questionsociety,nathanmelenbrink/theRecord,SachaG/Gamba,bengott/Telescope,JstnEdr/Telescope,bengott/Telescope,julienlapointe/telescope-nova-social-news,acidsound/Telescope,julienlapointe/telescope-nova-social-news,acidsound/Telescope,Air2air/Telescope,HelloMeets/HelloMakers,manriquef/Vulcan,JstnEdr/Telescope,jonmc12/heypsycho,TodoTemplates/Telescope,rtluu/immersive,Discordius/Telescope,jonmc12/heypsycho,dominictracey/Telescope,rtluu/immersive,basemm911/questionsociety,Air2air/Telescope,acidsound/Telescope,manriquef/Vulcan,SachaG/Zensroom,bshenk/projectIterate,manriquef/Vulcan,Discordius/Lesswrong2,HelloMeets/HelloMakers,Discordius/Telescope,TodoTemplates/Telescope,SachaG/Zensroom