align deploy target with RN template

avoids _objc_unsafeClaimAutoreleasedReturnValue error in xcode 8 when launching older versions of IOS

Author: hmedney

ios/React-Native-Webview-Bridge.xcodeproj/project.pbxproj

@@ -232,6 +232,7 @@
 					"$(SRCROOT)/../../../node_module/React/**",
 					"$(SRCROOT)/../../../node_modules/react-native/React/**",
 				);
+				IPHONEOS_DEPLOYMENT_TARGET = 8.0;
 				OTHER_LDFLAGS = "-ObjC";
 				PRODUCT_NAME = "$(TARGET_NAME)";
 				SKIP_INSTALL = YES;
@@ -246,6 +247,7 @@
 					"$(SRCROOT)/../../../node_module/React/**",
 					"$(SRCROOT)/../../../node_modules/react-native/React/**",
 				);
+				IPHONEOS_DEPLOYMENT_TARGET = 8.0;
 				OTHER_LDFLAGS = "-ObjC";
 				PRODUCT_NAME = "$(TARGET_NAME)";
 				SKIP_INSTALL = YES;