Add cocoapods support

CodableFirebase.podspec

@@ -0,0 +1,20 @@
+Pod::Spec.new do |s|
+  s.name = "CodableFirebase"
+  s.version = "0.0.3"
+  s.summary = "Use Codable with Firebase"
+  s.description = "This library helps you use your custom models that conform to Codable protocol with Firebase Realtime Database and Firestore"
+  s.homepage = "https://github.com/alickbass/CodableFirebase"
+  s.license = { :type => "MIT", :file => "LICENSE" }
+  s.author = { "Oleksii Dykan" => "alick_bass@mail.ru" }
+  
+  s.ios.deployment_target = "9.0"
+  s.osx.deployment_target = "10.11"
+  s.watchos.deployment_target = "2.0"
+  s.tvos.deployment_target = "9.0"
+  s.requires_arc = true
+
+  s.source = { :git => "https://github.com/alickbass/CodableFirebase.git", :tag => s.version, :branch => 'master'}
+  s.source_files = "CodableFirebase/*.swift"
+  s.pod_target_xcconfig = { 'SWIFT_VERSION' => '4' }
+
+end