Updated required iOS SDK version in source as well.

Author: jdee

ios/RNBranch.m

@@ -29,7 +29,7 @@
 static NSString * const RNBranchErrorDomain = @"RNBranchErrorDomain";
 static NSInteger const RNBranchUniversalObjectNotFoundError = 1;
 
-static NSString * const REQUIRED_BRANCH_SDK = @"0.27.0";
+static NSString * const REQUIRED_BRANCH_SDK = @"0.27.1";
 
 #pragma mark - Private RNBranch declarations