drop go1.8 and add go1.11

yuin · yuin · commit dab6e1e7e8fa · 2018-08-27T12:42:50.000+09:00
diff --git a/.travis.yml b/.travis.yml
@@ -1,9 +1,9 @@
 language: go
 
 go:
-  - "1.8"
   - "1.9"
   - "1.10"
+  - "1.11"
 
 before_install:
   - go get github.com/axw/gocov/gocov
