Switch to a README.md so we can get a Travis CI build status badge.
diff --git a/README b/README.md
similarity index 95%
rename from README
rename to README.md
index 5a03464..e66c64a 100644
--- a/README
+++ b/README.md
@@ -1,5 +1,7 @@
 Golint is a linter for Go source code.
 
+[![Build Status](https://travis-ci.org/golang/lint.svg?branch=master)](https://travis-ci.org/golang/lint)
+
 To install, run
   go get -u github.com/golang/lint/golint