Update podspec to include tvos as a deployment target

SocketRocket.podspec

@@ -9,11 +9,13 @@ Pod::Spec.new do |s|
   s.source_files       = 'SocketRocket/*.{h,m}'
   s.requires_arc       = true
 
-  s.ios.deployment_target = '6.0'
-  s.osx.deployment_target = '10.8'
+  s.ios.deployment_target  = '6.0'
+  s.osx.deployment_target  = '10.8'
+  s.tvos.deployment_target = '9.0'
 
   s.ios.frameworks     = 'CFNetwork', 'Security'
   s.osx.frameworks     = 'CoreServices', 'Security'
+  s.tvos.frameworks    = 'CFNetwork', 'Security'
 
   s.libraries          = "icucore"
 end