[offline] Upgrade to OfflineCore version 0.2

Also introduced the optimistic version operator, to avoid being stuck on an obsolete version.

[ci skip]

Author: Clément Le Provost

AlgoliaSearch-Offline-Swift.podspec

@@ -10,7 +10,7 @@ Pod::Spec.new do |s|
 
     s.ios.deployment_target = '8.0'
 
-    s.dependency 'AlgoliaSearchOfflineCore-iOS', '0.1'
+    s.dependency 'AlgoliaSearchOfflineCore-iOS', '~> 0.2'
 
     # Activate Core-dependent code.
     # WARNING: Specifying the preprocessor macro is not enough; it must be added to Swift flags as well.