companion: pin version

packages/@uppy/companion/package.json

@@ -34,7 +34,7 @@
     "atob": "2.1.0",
     "aws-sdk": "2.388.0",
     "body-parser": "1.18.2",
-    "chalk": "^2.4.2",
+    "chalk": "2.4.2",
     "common-tags": "1.8.0",
     "connect-redis": "3.4.0",
     "cookie-parser": "1.4.3",