Remove greenkeeper

The PRs are annoying, and it's quite therapeutic to upgrade manually…

.travis.yml

@@ -7,13 +7,10 @@ cache:
   yarn: true
   directories:
     - node_modules
-before_install: yarn global add greenkeeper-lockfile@1
-before_script: greenkeeper-lockfile-update
 script:
   - npm run lint
   - npm run lint-markdown
   - npm run test
-after_script: greenkeeper-lockfile-upload
 after_success:
   - npm run coverage
 env:

README.md

@@ -4,7 +4,6 @@ Command line tool for generating a changelog from git tags and commit history
 
 [![Latest npm version](https://img.shields.io/npm/v/auto-changelog.svg)](https://www.npmjs.com/package/auto-changelog)
 [![Build Status](https://img.shields.io/travis/CookPete/auto-changelog/master.svg)](https://travis-ci.org/CookPete/auto-changelog)
-[![Greenkeeper](https://img.shields.io/badge/greenkeeper-enabled-brightgreen.svg)](https://greenkeeper.io)
 [![Test Coverage](https://img.shields.io/codecov/c/github/cookpete/auto-changelog.svg)](https://codecov.io/gh/CookPete/auto-changelog)
 
 ### Installation