Don't Completely Mock Email Service

[steets250]

When testing out that emails send correctly, we should verify that the ejs parses the given data correctly. Rather than doing when(emailService.sendOrderConfirmation(member.email, member.firstName, anything())).thenResolve();, we should actually call the function, and only mock this.sendEmail(data);. This will ensure that in the event an error is thrown (e.g. log.warn('Failed to send order confirmation email to ${email}', { error });), then the tests will catch this error. Otherwise, we're relying on the assumption that the .ejs templates will pass.