companion: fix main field

packages/@uppy/companion/package.json

@@ -2,7 +2,7 @@
   "name": "@uppy/companion",
   "version": "1.3.0",
   "description": "OAuth helper and remote fetcher for Uppy's (https://uppy.io) extensible file upload widget with support for drag&drop, resumable uploads, previews, restrictions, file processing/encoding, remote providers like Dropbox and Google Drive, S3 and more :dog:",
-  "main": "lib/uppy.js",
+  "main": "lib/companion.js",
   "types": "types/index.d.ts",
   "author": "Transloadit.com",
   "license": "ISC",