React and Redux devtools (Electron Chromium extensions) fail to load

[danielweck]

[2] (node:6928) ExtensionLoadWarning: Warnings loading extension at /Users/danielweck/Library/Application Support/EDRLab.ThoriumReader/extensions/fmkadmapgofadopljbjfkapdkoienihi:
[2]   Unrecognized manifest key 'browser_action'.
[2]   Unrecognized manifest key 'minimum_chrome_version'.
[2]   Unrecognized manifest key 'update_url'.
[2]   Cannot load extension with file or directory name _metadata. Filenames starting with "_" are reserved for use by the system.
[2] 
[2]   readium-desktop:createLibraryWindow Added Extension:  React Developer Tools +0ms
[2]   readium-desktop:sync ### action type SHORTCUTS_SET +2ms
[2]   readium-desktop:main:redux:sagas:keyboard Keyboard shortcuts NOT saving (defaults): +7s
[2] (node:6928) ExtensionLoadWarning: Warnings loading extension at /Users/danielweck/Library/Application Support/EDRLab.ThoriumReader/extensions/lmhkpmbekcpmknklioeibfkpmmfibljd:
[2]   Unrecognized manifest key 'commands'.
[2]   Unrecognized manifest key 'homepage_url'.
[2]   Unrecognized manifest key 'page_action'.
[2]   Unrecognized manifest key 'short_name'.
[2]   Unrecognized manifest key 'update_url'.
[2]   Permission 'notifications' is unknown or URL pattern is malformed.
[2]   Permission 'contextMenus' is unknown or URL pattern is malformed.
[2]   Cannot load extension with file or directory name _metadata. Filenames starting with "_" are reserved for use by the system.
[2] 
[2]   readium-desktop:createLibraryWindow Added Extension:  Redux DevTools +2ms