Remove some unnecessary var self = this
Remove Component.prototype.ready override

We were using a flag self.display to indicate whether ready() should do
anything, and calling it ourselves when it should do something anyway.
Might as well just use our own function
Clean up some style problems

£FREE -> FREE
Monthly Payment -> Monthly payment
Membership Tier -> Membership tier
Remove a lot of duplicate js-membership-* classes

A lot of js-membership-* were being used to populate exactly the same
information
Rework change card form toggling

Removed animations in favour of a simple transition that achieves the
same effect without so much logic.
Simplify logic for show/hiding parts of the UI

"Partner" and "Patron" are no longer hardcoded magic strings, card
details should show if they present in the response from
/user/me/details.
Remove some tests

I don't think these tests really add any value and they force
formatAmount/formatDate to be scoped on the Membership object
Simplify change success message
Fix jshint errors
Merge branch 'master' into wpf-membership-tab-staff
Add QA selector
Remove unnecessary brackets
Merge pull request #7369 from guardian/wpf-membership-tab-staff

Membership tab clean up