Removed event bus and switched to vuex. Implemented vue dropzone.

assets/js/api/file.js

@@ -0,0 +1,20 @@
+import axios from 'axios';
+
+export default {
+    deleteFile: function (fileId) {
+        return axios.get(window.location.origin + '/file/delete/' + fileId);
+    },
+    getFiles: function (bookId) {
+        return axios.get(this.getFilesEndpoint(bookId), {
+            headers: {
+                'accept': 'application/json'
+            }
+        });
+    },
+    getFilesEndpoint: function (bookId) {
+        if (bookId) {
+            return `/api/books/${bookId}/files`;
+        }
+        return `/api/files`;
+    }
+}