Make stories exportable

Author: jantimon

lib/client-api/src/client_api.js

@@ -137,6 +137,7 @@ export default class ClientApi {
     let hasAdded = false;
     const api = {
       kind,
+      stories: {}
     };
 
     // apply addons
@@ -163,6 +164,7 @@ export default class ClientApi {
         });
       }
 
+      api.stories[storyName] = storyFn;
       const fileName = m && m.id ? `${m.id}` : undefined;
 
       const { hierarchyRootSeparator, hierarchySeparator } = this.getSeparators();