Fix issue while reading values from SEGGroupPayload in group() call (#90)
Fix issue while reading values from SEGGroupPayload in group() call (#90)

* Fix issue while reading values from SEGGroupPayload in group() call

* Fix [Amplitude setGroup:groupName:] call in SEGAmplitudeIntegration

Co-authored-by: Cody Garvin <34c36e3538fa224fa0e9d8b42a3d71a283f4ff72@gmail.com>
segment-integrations/analytics-ios-integration-amplitude,segment-integrations/analytics-ios-integration-amplitude