Add updates to make go releaser work in the future

See sensu/sensu-influxdb-handler#26

.travis.yml

@@ -14,14 +14,13 @@ script:
 - go test -v -race ./...
 before_script:
 - echo "REPO $TRAVIS_REPO_SLUG TAG ${TRAVIS_TAG}"
-before_deploy:
-- go get github.com/goreleaser/goreleaser
 deploy:
 - provider: script
-  script: goreleaser
+  script: curl -sL https://git.io/goreleaser | bash
   skip_cleanup: true
   on:
     tags: true
+    condition: $TRAVIS_OS_NAME = linux
 after_deploy:
 - git clone https://github.com/sensu/sensu-go-bonsai-asset.git bonsai
 - bonsai/generate-sha512sum.sh