multiple caampaign effects

Hi guys,

Would it be possible to estimate in one shot the **overall** and **individual** impact of multiple interventions directly in `CausalImpact`?
To give an example, I could be interested in estimating the effects of a set of multiple campaigns that took place for 2 months every 3 months in the last 2 years. I could estimate each intervention one by one, assuming independence between each other or controlling for the past interventions (like in issue #25?) and then aggregate the results.

Any suggestion?

Best wishes