Actions API :: ListPending, ListCompleted, ListAll

Add tests for ListPending and ListCompleted
Merge pull request #902 from johnweldon/api-impl-listpending

Actions API :: ListPending, ListCompleted, ListAll

Refactor and Expand API calls for Listing Actions
CharmInfo now contains charm Actions

This commit adds the apiserver test and endpoit to add Actions to the
CharmInfo api query response.