Update atomic-red-team.gemspec (#1719)

Updating email addresses to more relevant ones.

atomic-red-team.gemspec

@@ -3,7 +3,7 @@ Gem::Specification.new do |s|
   s.name        = 'atomic-red-team'
   s.version     = '1.0'
   s.authors     = ['Red Canary', 'Casey Smith', 'Mike Haag']
-  s.email       = ['it@redcanary.com', 'casey.smith@redcanary.com', 'mike.haag@redcanary.com']
+  s.email       = ['it@redcanary.com', 'opensource@redcanary.com']
   s.summary     = 'Small, highly portable, community developed detection tests mapped to ATT&CK.'
   s.license     = "MIT"
   s.homepage    = "https://redcanary.com/atomic-red-team"
@@ -12,4 +12,4 @@ Gem::Specification.new do |s|
   s.require_paths = %w(atomic_red_team)
 
   s.add_development_dependency 'github-pages'
-end
+end