shell() added pawershell detection

lib/osinfo.js

@@ -1120,7 +1120,28 @@ function shell(callback) {
   return new Promise((resolve) => {
     process.nextTick(() => {
       if (_windows) {
-        resolve('cmd');
+        try {
+          const result = 'CMD';
+          util.powerShell('$PSVersionTable').then(stdout => {
+            if (stdout) {
+              const lines = stdout.toString().toLowerCase().split('\n').map(line => line.replace(/ +/g, ' ').replace(/ +/g, ':'));
+              const ps = getValue(lines, 'psversion');
+              let result = 'CMD';
+              if (ps) {
+                result = `PowerShell ${ps.split('.')[0] + (ps.split('.')[1] ? '.' + ps.split('.')[1] : '')}`;
+              }
+            };
+            if (callback) {
+              callback(result);
+            }
+            resolve(result);
+          });
+        } catch {
+          if (callback) {
+            callback(result);
+          }
+          resolve(result);
+        }
       } else {
         let result = '';
         exec('echo $SHELL', function (error, stdout) {