Appium 1.5 Beta Release

What is out put of npm config list command? you need to set registry to https://registry.npmjs.org/ and try again.

Thanks @Priyank_Shah for responding.
I was able to solve the issue by setting the proxy using below commands,
npm config set proxy http://proxy.company.com:8080
npm config set https-proxy http://proxy.company.com:8080