added script which is updating version number in plugin.xml automatically

scripts/update-plugin-xml.js

@@ -0,0 +1,31 @@
+const args = process.argv.slice(2);
+const fs = require('mz/fs');
+const path = require('path');
+const xml2js = require('xml2js');
+const xmlPath = path.join(__dirname, '..', 'plugin.xml');
+
+const parse = xml => new Promise((resolve, reject) => {
+  const parser = new xml2js.Parser();
+
+  parser.parseString(xml, (error, result) => {
+    if (error) {
+      reject(error);
+    } else {
+      resolve(result);
+    }
+  });
+});
+
+const stringify = obj => {
+  const builder = new xml2js.Builder();
+
+  return builder.buildObject(obj);
+};
+
+fs.readFile(xmlPath, 'utf-8')
+  .then(xml => parse(xml))
+  .then(parsed => {
+    parsed.plugin.$.version = args[0];
+
+    return fs.writeFile(xmlPath, stringify(parsed));
+  });