Drop go 1.8 support

.travis.yml

@@ -1,7 +1,6 @@
 language: go
 
 go:
-  - "1.8.x"
   - "1.9.x"
   - "1.10.x"
   - "1.11.x"
@@ -28,5 +27,5 @@ script:
   - yarn test:verbose
   - gulp build
   - cd ..
-  - go vet $(go list ./... | grep -v '/vendor/')
-  - go test -v -race $(go list ./... | grep -v '/vendor/')
+  - go vet ./...
+  - go test -v -race ./...

README.md

@@ -21,7 +21,7 @@ There is a few different ways of getting it:
 - [Other versions](https://github.com/khlieng/dispatch/releases)
 
 ### 2. Go
-This requires a [Go environment](http://golang.org/doc/install), version 1.8 or greater.
+This requires a [Go environment](http://golang.org/doc/install), version 1.9 or greater.
 
 Fetch, compile and run dispatch:
 ```bash