Update Travis config

.travis.yml

@@ -1,31 +1,16 @@
-sudo: false
 language: go
-
+sudo: false
 go:
-  - 1.9.x
-  - 1.10.x
+  - "1.11.x"
   - tip
-
+os:
+  - linux
+  - osx
 matrix:
   allow_failures:
     - go: tip
-
-before_script:
-  - go get -u github.com/golang/lint/golint
-
+  fast_finish: true
 script:
-  - go test -race -coverprofile=coverage.txt -covermode=atomic
-
-after_script:
-  - test -z "$(gofmt -s -l -w . | tee /dev/stderr)"
-  - test -z "$(golint ./...     | tee /dev/stderr)"
-  - go vet ./...
-
+  - env GO111MODULE=on go test -race -coverprofile=coverage.txt -covermode=atomic
 after_success:
-  - bash <(curl -s https://codecov.io/bash)
-os:
-  - linux
-  - osx
-
-notifications:
-  email: false
+  - bash <(curl -s https://codecov.io/bash)