Allow Chaining

Often, subsequent operations depend on the preceding ones succeeding. Rather than a bunch of nested match statements, it'd be cool to somehow define a flow for success.

e.g. convert this to something better:

``` groovy
match Succeeded("result_1") on {
  success {
    match Succeeded(it) on {
       success {
         println "Something worked a lot!"
       }
     }
   }
}
```
