message: Remove Node 4 and 5 from Travis CI tests.
diff: @@ -2,28 +2,17 @@ language: node_js
  matrix:
  include:
  - node_js: "11"
  - env: NPM_VERSION=""
  - node_js: "10"
  - env: NPM_VERSION=""
  - node_js: "9"
  - env: NPM_VERSION=""
  - node_js: "8"
  - env: NPM_VERSION=""
  - node_js: "7"
  - env: NPM_VERSION=""
  - node_js: "6"
  - env: NPM_VERSION=""
  - - node_js: "5"
  - env: NPM_VERSION="@5"
  - - node_js: "4"
  - env: NPM_VERSION="@5"
  # Allow Travis tests to run in containers.
  sudo: false
  # Update package-lock.json after test runs:
  before_install:
  - - npm install -g npm$NPM_VERSION
  - npm install -g greenkeeper-lockfile@1
  before_script: greenkeeper-lockfile-update
  after_script: greenkeeper-lockfile-upload
  