Create CircleCI config.yml (#519)

* Create config.yml
* Delete .travis.yml
* Added CircleCI badge to README
* Add golint; run on latest only

.circleci/config.yml

@@ -0,0 +1,76 @@
+version: 2.0
+
+jobs:
+  # Base test configuration for Go library tests Each distinct version should
+  # inherit this base, and override (at least) the container image used.
+  "test": &test
+    docker:
+      - image: circleci/golang:latest
+    working_directory: /go/src/github.com/gorilla/websocket
+    steps: &steps
+      - checkout
+      - run: go version
+      - run: go get -t -v ./...
+      # Only run gofmt, vet & lint against the latest Go version
+      - run: >
+          if [[ "$LATEST" = true ]]; then
+            go get -u golang.org/x/lint/golint
+            golint ./...
+          fi
+      - run: >
+          if [[ "$LATEST" = true ]]; then
+            diff -u <(echo -n) <(gofmt -d .)
+          fi
+      - run: >
+          if [[ "$LATEST" = true ]]; then
+            go vet -v .
+          fi
+      - run: if [[ "$LATEST" = true ]]; then go vet -v .; fi
+      - run: go test -v -race ./...
+
+  "latest":
+    <<: *test
+    environment:
+      LATEST: true
+
+  "1.12":
+    <<: *test
+    docker:
+      - image: circleci/golang:1.12
+
+  "1.11":
+    <<: *test
+    docker:
+      - image: circleci/golang:1.11
+
+  "1.10":
+    <<: *test
+    docker:
+      - image: circleci/golang:1.10
+
+  "1.9":
+    <<: *test
+    docker:
+      - image: circleci/golang:1.9
+
+  "1.8":
+    <<: *test
+    docker:
+      - image: circleci/golang:1.8
+
+  "1.7":
+    <<: *test
+    docker:
+      - image: circleci/golang:1.7
+
+workflows:
+  version: 2
+  build:
+    jobs:
+      - "latest"
+      - "1.12"
+      - "1.11"
+      - "1.10"
+      - "1.9"
+      - "1.8"
+      - "1.7"

README.md

@@ -1,11 +1,11 @@
 # Gorilla WebSocket
 
+[![GoDoc](https://godoc.org/github.com/gorilla/websocket?status.svg)](https://godoc.org/github.com/gorilla/websocket)
+[![CircleCI](https://circleci.com/gh/gorilla/websocket.svg?style=svg)](https://circleci.com/gh/gorilla/websocket)
+
 Gorilla WebSocket is a [Go](http://golang.org/) implementation of the
 [WebSocket](http://www.rfc-editor.org/rfc/rfc6455.txt) protocol.
 
-[![Build Status](https://travis-ci.org/gorilla/websocket.svg?branch=master)](https://travis-ci.org/gorilla/websocket)
-[![GoDoc](https://godoc.org/github.com/gorilla/websocket?status.svg)](https://godoc.org/github.com/gorilla/websocket)
-
 ### Documentation
 
 * [API Reference](http://godoc.org/github.com/gorilla/websocket)

conn_test.go

@@ -297,7 +297,7 @@ func TestWriteBufferPoolSync(t *testing.T) {
 // errorWriter is an io.Writer than returns an error on all writes.
 type errorWriter struct{}
 
-func (ew errorWriter) Write(p []byte) (int, error) { return 0, errors.New("Error!") }
+func (ew errorWriter) Write(p []byte) (int, error) { return 0, errors.New("error") }
 
 // TestWriteBufferPoolError ensures that buffer is returned to pool after error
 // on write.