travis: add testing for go tip allowing failure
@@ -2,11 +2,16 @@ sudo: false
language: go
-# Versions of go that are explicitly supported by gonum.
+# Versions of go that are explicitly supported by gonum plus go tip.
go:
- 1.6.x
- 1.7.x
- 1.8.x
+ - master
+
+matrix:
+ allow_failures:
+ - go: master
before_install:
# Required for format check.
