Assets are not being versioned correctly

[bporcelli]

Simple Sales Tax scripts and stylesheets are not being versioned properly - the ?ver query parameter is being set to the current WordPress version rather than the current SST plugin version. This can potentially result in stale versions of styles/scripts being loaded on server setups with caching enabled.

I suspect this is contributing to issues like the one reported in https://wordpress.org/support/topic/8-0-0-exemption-certificates-very-broken/