For those of you who were concerned about LastPass:

https://www.engadget.com/2017/10/13/lastpass-beta-firefox-57-webextension/

The beta version is available now - The final version will be ready when the browser arrives on November 14th.

As I mentioned earlier, for those who want to use a GPLv3 product, check out Bitwarden: 

https://addons.mozilla.org/en-US/firefox/addon/bitwarden-password-manager/