fix travis releases

Author: nicpottier

Diff for: .travis.yml

@@ -20,5 +20,6 @@ script:
 after_success:
 - bash <(curl -s https://codecov.io/bash)
 - rm coverage.text
+- rm elasticsearch-6.2.3.deb
 - test -n "$TRAVIS_TAG" && curl -sL https://git.io/goreleaser | bash