Charge: Make subscription plan on submit

Work in progress on subscribing a client to a plan.
Make a subscription plan, but do nothing with
it at this moment. Next step is to associate
a client with the plan.
Charge: Create customer on submit

Work in progress, create a customer when the submit
payment button is pressed. At this point, we need a
notion of a person's account before we can proceed
in a sane matter. Once accounts have been created
on our side, the work started here can continue.
Add passport dependency

Add a dependency to passportjs and the passport-google
strategy, for use with logging in to the site.
Add simple authorization layer

Use passportjs with the Google OpenID strategy to log in.
Isn't hooked up to anything useful, yet -- we're just at
an ok stopping point.
Add 'log in' link to the top

Add a link that logs the user in via the
Google auth mechanism. Put the header at
the top of each partial for the time being,
versus putting it in index.html,so that we
can access it in the Angular app / view.
Add '/whoami' to get logged in user

Make it easy for the client to determine who is
logged in, if anyone. Returns 'anonymous' if
nobody has been authenticated, otherwise returns
the user id, which is the email address.
Show logged in user at the top of the page

Use /whoami to get the current user's id, and
display it in the header. Also make it easy to
log out -- obviously in a way that will be
redesigned.