0.4.3

• New #118: Add PaidMediaPurchased type.
• New #118: Add purchasedPaidMedia field to Update type.
• New #118: Add paidMediaPayload field to TransactionPartnerUser type.
• New #118: Add payload parameter to SendPaidMedia method.
• New #118: Add prizeStarCount field to GiveawayCreated, Giveaway, GiveawayWinners and
  ChatBoostSourceGiveaway types.
• New #118: Add isStarGiveaway field to GiveawayCompleted type.
• Enh #118: Bump php-http/multipart-stream-builder dependency to ^1.4.2 version.