Update podspec

Author: Tyler Fox

INTUAnimationEngine.podspec

@@ -1,11 +1,11 @@
 Pod::Spec.new do |s|
   s.name                  = "INTUAnimationEngine"
-  s.version               = "1.2.0"
+  s.version               = "1.3.0"
   s.homepage              = "https://github.com/intuit/AnimationEngine"
   s.license               = { :type => 'MIT', :file => 'LICENSE' }
   s.author                = { "Tyler Fox" => "tyler_fox@intuit.com" }
-  s.source                = { :git => "https://github.com/intuit/AnimationEngine.git", :tag => "v1.2.0" }
-  s.source_files          = 'Source'
+  s.source                = { :git => "https://github.com/intuit/AnimationEngine.git", :tag => "v1.3.0" }
+  s.source_files          = 'INTUAnimationEngine/*.{h,m}'
   s.platform              = :ios
   s.ios.deployment_target = '5.0'
   s.requires_arc          = true
@@ -18,4 +18,8 @@ Pod::Spec.new do |s|
   INTUAnimationEngine includes an extensive library of easing functions that can be used to customize animation timing. A complete library of interpolation functions is also included to animate any type of value or property, including those that are not animatable by Core Animation.
   DESC
 
+  s.subspec 'SpringSolver' do |ss|
+    ss.source_files = 'INTUAnimationEngine/SpringSolver/*.{h,c}'
+    ss.license      = { :type => 'BSD', :file => 'LICENSE-SpringSolver' }
+  end
 end