Add ability to specify site_id for each call, overriding the global value

[stevehanson]

I work for a SaaS studio-membership company, and we use this gem to allow our members to book classes at any MindBody studio that we partner with.

This gem currently has a globally-set site_id that is used for each API call, which makes it difficult to use this gem to interface with multiple studios. I've monkey-patched my version of this gem to allow overriding the site_id on any request by passing in a site_id param as a local when making the request, eg:

MindBody::Services::SaleService.checkout_shopping_cart(site_id: "123456", ...)

I was wondering if this is functionality you'd be interested in including in this gem, and if so, would be happy to start a discussion in this thread and submit a PR once an approach is decided on. If not, no worries either.

[wingrunr21]

You mean via #17 when we discussed this previously? 😄

I'm going to close this issue but I'm happy to discuss further in #17.

[stevehanson]

Hah, wow, completely forgot about that 😄