language: go
go:
  - 1.4
  - 1.5
  - 1.6
  - tip
install: go get -v ./collins
script: go test -v ./collins

language: go
go:
  - 1.4
  - 1.5
  - 1.6
  - 1.7
  - 1.8
  - tip
install: go get -v ./collins
script: go test -v ./collins

Add new versions of go to test against
Add new versions of go to test against

Not sure what go looks like internally at tumblr but from this page https://golang.org/doc/devel/release.html it looks like it's only worth trying to keep support for 1.7 and 1.8. I have recently really come to appreciate people who don't break backwards compatibility for no real reason however.