Flagship

**Added:**

- Visitor instance management
- Flag management class
- Hits are now sent with a batch processing system

**Changed:**

- SDK new architecture
- Init and configuration
- synchronizeModification / getModification / getModificationInfo / activateModification are now obsolete and have been replaced by Flag class

Fix:
- Prevent conflicts with Typing dependency
Removed:
- Pytest dependency from requirements

Fix Event hit value type: must be integer > 0