README: explicitly state version support policy
MODIFY
.travis.yml
.travis.yml
@@ -2,6 +2,7 @@ sudo: false
language: go
+# Do not move these lines; they are referred to by README.md.
# Versions of go that are explicitly supported by gonum plus go tip.
go:
- 1.8.x

MODIFY
README.md
README.md
@@ -8,6 +8,11 @@ Installation is done using `go get`.
go get -u gonum.org/v1/gonum/...
```
+## Supported Go versions
+
+Gonum supports and tests on the [three most recent major versions of Go](https://github.com/gonum/gonum/blob/master/.travis.yml#L6-L11).
+
+
## Build tags
The gonum packages use a variety of build tags to set non-standard build conditions.

README: explicitly state version support policy