Removed unnecessary getBulk in PostsRepository

refs https://github.com/TryGhost/Arch/issues/16

- The method ended up being used only once, so it makes no sense to complicate the interface without any gain.

ghost/collections/src/CollectionsService.ts

@@ -105,7 +105,6 @@ type QueryOptions = {
 
 interface PostsRepository {
     getAll(options: QueryOptions): Promise<CollectionPost[]>;
-    getBulk(ids: string[], transaction?: Knex.Transaction): Promise<CollectionPost[]>;
 }
 
 export class CollectionsService {
@@ -392,8 +391,10 @@ export class CollectionsService {
     }
 
     async updatePostsInCollections(postIds: string[], collections: Collection[], transaction: Knex.Transaction) {
-        const posts = await this.postsRepository.getBulk(postIds, transaction);
-
+        const posts = await this.postsRepository.getAll({
+            filter: `id:[${postIds.join(',')}]`,
+            transaction: transaction
+        });
 
         for (const collection of collections) {
             for (const post of posts) {

ghost/collections/test/fixtures/PostsRepositoryInMemory.ts

@@ -10,10 +10,4 @@ export class PostsRepositoryInMemory extends InMemoryRepository<string, Collecti
             tags: entity.tags.map(tag => tag.slug)
         };
     }
-
-    async getBulk(ids: string[]) {
-        return this.getAll({
-            filter: `id:[${ids.join(',')}]`
-        });
-    }
 }