try ruby 2.6

.travis.yml

@@ -9,8 +9,6 @@ addons:
   apt:
     packages:
     - ruby-dev
-    - ruby
-    - rubygems
     - rpm
     - build-essential
     - git
@@ -27,9 +25,8 @@ services:
 install:
   - mkdir -p $(go env GOPATH)/bin
   - curl -sfL https://install.goreleaser.com/github.com/golangci/golangci-lint.sh | sh -s -- -b $(go env GOPATH)/bin latest
-  - rvm install 2.3.0
-  - rvm 2.3.0 do gem install --no-document fpm
-  - rvm 2.3.0 pkg install zlib
+  - rvm install 2.6.0
+  - rvm 2.6.0 do gem install --no-document fpm
 before_script:
   # Create your own deploy key, tar it, and encrypt the file to make this work. Optionally add a bitly_token file to the archive.
   - openssl aes-256-cbc -K $encrypted_43c29b766863_key -iv $encrypted_43c29b766863_iv -in .secret_files.tar.enc -out .secret_files.tar -d
@@ -44,7 +41,7 @@ script:
   # Test built docker image.
   - docker run $BINARY -v 2>&1 | grep -Eq "^$BINARY, version $VERSION"
   # Build everything
-  - rvm 2.3.0 do make release
+  - rvm 2.6.0 do make release
 after_success:
   # Display Release Folder
   - ls -l release/