Update podspec to use subspec of KSCrash

Author: HazAT

SentryReactNative.podspec

@@ -18,8 +18,7 @@ Pod::Spec.new do |s|
   s.preserve_paths = '*.js'
 
   s.dependency 'React'
-  s.dependency 'Sentry', '~> 3.0.1'
-  s.dependency 'KSCrash', '~> 1.15.8'
+  s.dependency 'Sentry/KSCrash', '~> 3.0.4'
 
   s.source_files = 'ios/RNSentry*.{h,m}'
   s.public_header_files = 'ios/RNSentry.h'