Ability to specify browser during authentication

[anujmaurice]

Is your feature request related to a problem? Please describe.
Everytime a web authentication is required, the browser that is launched is the system's default browser. The default browser is not always configured with the right google account, For eg, my default browser is firefox and it is configured with my work account. It will be a good feature for user to mention which browser to launch. webbrowser module supports this feature already

Describe the solution you'd like
I have made the change to specify which browser needs to be launched