Update CHANGELOG.md

Merge pull request #54 from AppsFlyerSDK/dev/update-6.13.1

Dev/update 6.13.1

Merge pull request #53 from AppsFlyerSDK/dev/DELIVERY-54559/update-6.…

…13.0

Dev/delivery 54559/update 6.13.0

Merge pull request #45 from AppsFlyerSDK/releases/6.5.4.0

Releases/6.5.4.0

Update CHANGELOG.md

Update CHANGELOG.md

Merge pull request #37 from AppsFlyerSDK/releases/6.3.2.0

Releases/6.3.2.0

Merge pull request #36 from AppsFlyerSDK/releases/6.3.0.0

SDK 6.3.0 update