Rename isSecurityCodeValid to isCVVValid

[remear]

Fixes #70

[mjallday]

@remear i almost forgot that this is a breaking change. we should alias the old command to this until we have a chance to update any users of this feature and #75 too.

[matthewfl]

this is just going out on rev1 right? so there should not be any real problems with this breaking change right?

[mjallday]

The dashboard would break until we deployed a new version since it's pegged at the minor version, not the build.

[matthewfl]

I think it would be easier then to just deploy both of these updates at the same, while that is not as "clean" I feel that is better then having soon to be dead code in balanced.js