6.0.0-beta2

• Convert BraintreePayPal module to Swift
• Breaking Changes
  • BraintreePayPal
    • Rename BTPayPalRequest.riskCorrelationId to BTPayPalRequest.riskCorrelationID
    • Removed BTPayPalRequest.activeWindow property
      • The window will be set to the first window or a new ASPresentationAnchor if the first window is nil
    • Update BTPayPalRequestLandingPageType enum default case to .none
      • Update enum values
        • .none = 0
        • .login = 1
        • .billing = 2
    • BTPayPalRequestUserAction
      • Update enum cases to .none and .payNow
      • Update enum values
        • .none = 0
        • .payNow = 1
    • Update BTPayPalRequestIntent enum values
      • .authorize = 0
      • .sale = 1
      • .order = 2
    • Update BTPayPalLineItemKind enum values
      • .debit = 0
      • .credit = 1
    • Create BTPayPalLocaleCode enum
    • BTPayPalRequest.localeCode now uses the BTPayPalLocaleCode enum instead of a String
    • Renamed and replaced BTPayPalClient.tokenizePayPalAccount with two methods called tokenize() taking in requests of either BTPayPalCheckoutRequest or BTPayPalVaultRequest
    • Removed BTPayPalErrorType
    • Replaced BTPayPalErrorDomain global constant with BTPayPalError.errorDomain
    • Added BTPayPalError
      • .disabled
      • .canceled
      • .fetchConfigurationFailed
      • .httpPostRequestError
      • .invalidURL
      • .asWebAuthenticationSessionURLInvalid
      • .invalidURLAction
      • .failedToCreateNonce
    • Make BTPayPalNonce initializer internal
  • BraintreePayPalNativeCheckout (BETA)
    • Renamed and replaced BTPayPalNativeCheckoutClient.tokenizePayPalAccount with two methods called tokenize() taking in requests of either BTPayPalNativeCheckoutRequest or BTPayPalNativeVaultRequest
    • BTPayPalNativeCheckoutRequest now takes in an intent of type BTPayPalRequestIntent instead of BTPayPalNativeRequestIntent
    • BTPayPalNativeCheckoutRequest.localeCode now uses the BTPayPalLocaleCode enum instead of a String value
  • BraintreeUnionPay
    • Remove BraintreeUnionPay module
      • UnionPay cards can now be processed as regular cards (through the BraintreeCard module) due to their partnership with Discover
  • BraintreeCore
    • Remove BTConfiguration+Extensions.isUnionPayEnabled property
    • Remove BTPreferredPaymentMethods and BTPreferredPaymentMethodResult
  • BraintreeSEPADirectDebit
    • The tokenize method no longer takes in a context parameter
    • Merchants no longer need to conform to the ASWebAuthenticationPresentationContextProviding protocol