v142 (heroku#407)

v141 (heroku#405)

Merge pull request heroku#396 from heroku/go-1-14-no-vendor

make `go list` use of -mod=vendor more dynamic

Merge pull request heroku#397 from heroku/v139

v139

Merge pull request heroku#393 from telendt/master

Add go1.13.8 and go1.14

Merge pull request heroku#388 from heroku/da/release-v137

Release v137

Merge pull request heroku#381 from heroku/update-go-version

Add go1.13.4, go1.13.5, go1.12.13, go1.12.14

Merge pull request heroku#351 from heroku/ffz/RemoveHgANDBzr

Remove hg and bzr

Merge pull request heroku#374 from heroku/go1.13.3_1.12.12

add go1.13.3 and go1.12.12

Merge pull request heroku#371 from heroku/ffz/BumpGolangCILint

Bump golangci-lint to 1.20.0