Bring Go current in Travis

Author: gliptak

.travis.yml

@@ -3,10 +3,14 @@ language: go
 sudo: false
 
 go:
-  - "1.10.x"
   - "1.11.x"
+  - "1.12.x"
   - tip
 
+matrix:
+    allow_failures:
+        - go: tip
+
 script:
   - ./.travis.gofmt.sh
   - go test -cover ./...