Ionic build error on ios

I am getting an error while I try to build using the command:
ionic build ios

Error: Cannot find module ‘cordova-js/tasks/lib/bundle-browserify’

Also I get error while i try to add platform ios using the command:
ionic platform add ios

Error: Cannot find module ‘npmconf’

Here are my ionic info :

Cordova CLI: 5.4.1
Ionic Framework Version: 2.0.1
Ionic CLI Version: 2.2.1
Ionic App Lib Version: 2.2.0
Ionic App Scripts Version: 1.1.0
ios-deploy version: 1.7.0
ios-sim version: 5.0.1
OS: OS X El Capitan
Node Version: v7.2.1
Xcode version: Xcode 8.1 Build version 8B62

I am new to ionic framework.
What should i do now to install the app on my iPhone ?