remove Sourcery dependency from sample project

Author: Christian

Example/Podfile

@@ -3,11 +3,9 @@ use_frameworks!
 target 'NotesExample-iOS' do
   platform :ios, :deployment_target => '11.0'
   pod 'ObjectBox'
-  pod 'Sourcery'
 end
 
 target 'NotesExample-macOS' do
   platform :osx, :deployment_target => '10.10'
   pod 'ObjectBox'
-  pod 'Sourcery'
 end