Ensured platform is set as it is a required field for payload_data (fixes #206)
Ensured platform is set as it is a required field for payload_data (fixes #206)

chunkyguy/snowplow-objc-tracker,snowplow/snowplow-objc-tracker,iamjason/snowplow-objc-tracker,snowplow/snowplow-objc-tracker,snowplow/snowplow-objc-tracker,iamjason/snowplow-objc-tracker,chunkyguy/snowplow-objc-tracker,snowplow/snowplow-objc-tracker,iamjason/snowplow-objc-tracker,redengineer/snowplow-objc-tracker,redengineer/snowplow-objc-tracker