chore(ci): drop greenkeeper support (external-secrets#318)

.travis.yml

@@ -6,17 +6,13 @@ matrix:
  fast_finish: true
  include:
  - node_js: '12'
-# https://github.com/greenkeeperio/greenkeeper-lockfile#npm
 before_install:
 # package-lock.json was introduced in npm@5
 - '[[ $(node -v) =~ ^v9.*$ ]] || npm install -g npm@latest' # skipped when using node 9
-- npm install -g greenkeeper-lockfile
 # kubectl, kind, helm
 - curl -LO https://storage.googleapis.com/kubernetes-release/release/$(curl -s https://storage.googleapis.com/kubernetes-release/release/stable.txt)/bin/linux/amd64/kubectl && chmod +x kubectl && sudo mv kubectl /usr/local/bin/
 - curl -Lo kind https://github.com/kubernetes-sigs/kind/releases/download/v0.5.1/kind-linux-amd64 && chmod +x kind && sudo mv kind /usr/local/bin/
 - curl -Lo helm.tgz https://get.helm.sh/helm-v2.16.0-linux-amd64.tar.gz && tar -zxvf helm.tgz && sudo mv linux-amd64/helm /usr/local/bin/helm
-before_script: greenkeeper-lockfile-update
-after_script: greenkeeper-lockfile-upload
 install: npm install
 script:
 - npm test