finish gradients refactor

ios/ViewManagers/RNSVGLinearGradientManager.m

@@ -0,0 +1,27 @@
+/**
+ * Copyright (c) 2015-present, Horcrux.
+ * All rights reserved.
+ *
+ * This source code is licensed under the MIT-style license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+#import "RNSVGLinearGradientManager.h"
+#import "RNSVGLinearGradient.h"
+
+@implementation RNSVGLinearGradientManager
+
+RCT_EXPORT_MODULE()
+
+- (RNSVGNode *)node
+{
+  return [RNSVGLinearGradient new];
+}
+
+RCT_EXPORT_VIEW_PROPERTY(x1, NSString)
+RCT_EXPORT_VIEW_PROPERTY(y1, NSString)
+RCT_EXPORT_VIEW_PROPERTY(x2, NSString)
+RCT_EXPORT_VIEW_PROPERTY(y2, NSString)
+RCT_EXPORT_VIEW_PROPERTY(gradient, NSArray<NSNumber *>)
+
+@end