refactor: flow typing (#1012)

* fix: padding

* fix: Minor button alignment issues

* feat: Add icon to invite people button

* WIP

app/utils/getDataTransferFiles.js

@@ -1,5 +1,5 @@
 // @flow
-export default function getDataTransferFiles(event: SyntheticEvent<*>): File[] {
+export default function getDataTransferFiles(event: SyntheticEvent<>): File[] {
   let dataTransferItemsList = [];
 
   // $FlowFixMe

app/utils/importFile.js

@@ -1,9 +1,10 @@
 // @flow
-import Document from '../models/Document';
+import Document from 'models/Document';
+import DocumentsStore from 'stores/DocumentsStore';
 
 type Options = {
   file: File,
-  documents: *,
+  documents: DocumentsStore,
   collectionId: string,
   documentId?: string,
 };