Update config and podspec

MessageKit.podspec

@@ -11,17 +11,11 @@ Pod::Spec.new do |s|
    s.source = { :git => 'https://github.com/MessageKit/MessageKit.git', :tag => s.version }
    s.source_files = 'Sources/**/*.swift'
 
-   s.pod_target_xcconfig = {
-      "SWIFT_VERSION" => "5.0",
-   }
-
    s.swift_version = '5.0'
 
    s.ios.deployment_target = '9.0'
    s.ios.resource_bundle = { 'MessageKitAssets' => 'Assets/MessageKitAssets.bundle/Images' }
 
-   s.requires_arc = true
-
    s.dependency 'InputBarAccessoryView', '~> 4.3.0'
 
 end