add new go versions to test matrix (#9)

update test matrix to include new golang versions 1.10.x and 1.11.x, removed golint from build job

.travis.yml

@@ -6,15 +6,14 @@ go:
   - 1.7.x
   - 1.8.x
   - 1.9.x
+  - 1.10.x
+  - 1.11.x
   - tip
 
-before_install:
-  - go get -v github.com/golang/lint/golint
-
 script:
   - go fmt $(go list ./... | grep -v /vendor/)
   - go vet $(go list ./... | grep -v /vendor/)
   - go test -race $(go list ./... | grep -v /vendor/)
 
 notifications:
-  email: false
+  email: false