Remove sourceIdentifier from BUYCheckout.

Mobile Buy SDK/Mobile Buy SDK Tests/BUYClientTest.m

@@ -90,7 +90,6 @@
 	NSDictionary *dict = @{@"checkout":
 							   @{@"line_items": @[],
 								 @"source_name": @"mobile_app",
-								 @"source_identifier": self.client.appId,
 								 @"marketing_attribution":@{@"medium": @"iOS", @"source": self.client.applicationName}}};
 	
 	NSDictionary *json = [NSJSONSerialization JSONObjectWithData:data options:0 error:nil];

Mobile Buy SDK/Mobile Buy SDK/Data/BUYClient.m

@@ -300,7 +300,6 @@ static NSString *const kBUYClientPathCollectionPublications = @"collection_listi
 {
 	checkout.marketingAttribution = @{@"medium": @"iOS", @"source": self.applicationName};
 	checkout.sourceName = @"mobile_app";
-	checkout.sourceIdentifier = self.appId;
 	if (self.urlScheme || checkout.webReturnToURL) {
 		checkout.webReturnToURL = checkout.webReturnToURL ?: self.urlScheme;
 		checkout.webReturnToLabel = checkout.webReturnToLabel ?: [@"Return to " stringByAppendingString:self.applicationName];

Mobile Buy SDK/Mobile Buy SDK/Models/BUYCheckout.h

@@ -220,11 +220,6 @@
 @property (nonatomic, copy, readonly) NSString *sourceName;
 
 /**
- *  The unique identifier for the source: the appId
- */
-@property (nonatomic, copy, readonly) NSString *sourceIdentifier;
-
-/**
  *  Credit card stored on the checkout
  */
 @property (nonatomic, strong, readonly) BUYMaskedCreditCard *creditCard;

Mobile Buy SDK/Mobile Buy SDK/Models/BUYCheckout.m

@@ -154,7 +154,6 @@
 	self.termsOfServiceURL = [NSURL buy_urlWithString:dictionary[@"terms_of_service_url"]];
 	
 	self.sourceName = dictionary[@"source_name"];
-	self.sourceIdentifier = dictionary[@"source_identifier"];
 }
 
 - (NSString *)shippingRateId

Mobile Buy SDK/Mobile Buy SDK/Models/BUYCheckout_Private.h

@@ -53,5 +53,4 @@
 @property (nonatomic, strong) NSURL *refundPolicyURL;
 @property (nonatomic, strong) NSURL *termsOfServiceURL;
 @property (nonatomic, copy) NSString *sourceName;
-@property (nonatomic, copy) NSString *sourceIdentifier;
 @end