handle transactions on paypal webhook

src/Core/Enums/GatewayType.cs

@@ -13,6 +13,8 @@ namespace Bit.Core.Enums
         [Display(Name = "Google Play Store")]
         PlayStore = 3,
         [Display(Name = "Coinbase")]
-        Coinbase = 4
+        Coinbase = 4,
+        [Display(Name = "PayPal")]
+        PayPal = 1,
     }
 }

src/Core/Enums/TransactionType.cs

@@ -5,6 +5,7 @@
         Charge = 0,
         Credit = 1,
         PromotionalCredit = 2,
-        ReferralCredit = 3
+        ReferralCredit = 3,
+        Refund = 4,
     }
 }