Bump version to 4.1.1

[CI] Fix python version spec regression

refresh tokens (#50)

* refresh token if expired on access to service

* add refresh in Message

* update version

case insensitive header check

signature bug fix

Merge branch 'master' of https://github.com/jeremyephron/simplegmail

Merge branch 'master' of https://github.com/jeremyephron/simplegmail

Merge pull request #38 from jeremyephron/spam_trash_bugfix

used include_spam_trash

Gmail: creds_file param reversion fix

Merge branch 'roib20-patch-1'