Fix deployment target

Author: Vlad

CalendarManager.podspec

@@ -6,7 +6,7 @@ Pod::Spec.new do |s|
   s.homepage     = "http://www.shoutem.com"
   s.license      = { :type => "BSD" }
   s.author       = { "Vladimir Vdović" => "vlad@definitely-not-vlad.com" }
-  s.platforms    = { :ios => "10.0" }
+  s.platforms    = { :ios => "8.0" }
   s.source       = { :git => "https://github.com/shoutem/react-native-calendar-manager.git", :tag => "1.0" }
 
   s.source_files = '**/*.{h,m}'