Update Siren.podspec

Author: ArtSabintsev

Siren.podspec

@@ -14,7 +14,7 @@ Siren is actively maintained by Arthur Sabintsev and Aaron Brager.
   s.homepage     = "https://github.com/ArtSabintsev/Siren"
   s.license      = "MIT"
   s.authors      = { "Arthur Ariel Sabintsev" => "[email protected]", "Aaron Brager" => "[email protected]" }
-  s.platform     = :ios, "8.0"
+  s.platform     = :ios, "9.0"
   s.source       = { :git => "https://github.com/ArtSabintsev/Siren.git", :tag => s.version.to_s }
   s.source_files = 'Siren/Siren.swift'
   s.resources    = 'Siren/Siren.bundle'