Merge pull request getredash#3196 from getredash/master Sync release/6.0.x branch with master

WIP: Update CHANGELOG (getredash#3159) 

Bump version 

Add auth via JWT providers (getredash#2768) * authentication via JWT providers * add support for IAP JWT auth * remove jwt_auth Blueprint and /headers endpoint * fix pep8: imports

Merge branch 'master' of github.com:getredash/redash 

Update version 

Update v5-beta release date. 

Version bump to 4.0.1 

Merge branch 'master' of github.com:getredash/redash 

Merge pull request getredash#2369 from getredash/query-refresh Add: configuration for query refresh intervals.