Merge pull request #139 from kejinliang/master

Update RNFetchBlobNetwork.m

package.json

 {
-  "name": "fetchblob-dev",
+  "name": "react-native-fetch-blob",
   "version": "0.9.5",
   "private": true,
   "scripts": {

src/ios/RNFetchBlobNetwork.m

             if(![fm fileExistsAtPath:folder]) {
                 [fm createDirectoryAtPath:folder withIntermediateDirectories:YES attributes:NULL error:nil];
             }
-            [fm createFileAtPath:destPath contents:[[NSData alloc] init] attributes:nil];
+            if (![fm fileExistsAtPath:destPath]) {
+                [fm createFileAtPath:destPath contents:[[NSData alloc] init] attributes:nil];
+            }
             writeStream = [[NSOutputStream alloc] initToFileAtPath:destPath append:YES];
             [writeStream scheduleInRunLoop:[NSRunLoop currentRunLoop] forMode:NSRunLoopCommonModes];
             [writeStream open];