update electron to v43

electron/node_modules/unzipper/lib/BufferStream.js

@@ -0,0 +1,19 @@
+const Stream = require('stream');
+
+module.exports = function(entry) {
+  return new Promise(function(resolve, reject) {
+    const chunks = [];
+    const bufferStream = Stream.Transform()
+      .on('finish', function() {
+        resolve(Buffer.concat(chunks));
+      })
+      .on('error', reject);
+
+    bufferStream._transform = function(d, e, cb) {
+      chunks.push(d);
+      cb();
+    };
+    entry.on('error', reject)
+      .pipe(bufferStream);
+  });
+};