Update .travis.yml

Author: razonyang

.travis.yml

@@ -19,4 +19,4 @@ script:
   - go test -v -covermode=count -coverprofile=coverage.out ./...
   - go vet ./...
   - test -z "$(gofmt -d -s . | tee /dev/stderr)"
-  - $HOME/gopath/bin/goveralls  -coverprofile=coverage.out -service=travis-ci
+  - $HOME/gopath/bin/goveralls -coverprofile=coverage.out -service=travis-ci