docs(readme): add Greenkeeper badge

Author: greenkeeper[bot]

README.md

@@ -1,7 +1,7 @@
 # fastify-oracle
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 [![Build Status](https://travis-ci.org/cemremengu/fastify-oracle.svg?branch=master)](https://travis-ci.org/cemremengu/fastify-oracle)
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+[![Coverage Status](https://coveralls.io/repos/github/cemremengu/fastify-oracle/badge.svg?branch=master)](https://coveralls.io/github/cemremengu/fastify-oracle?branch=master) [![Greenkeeper badge](https://badges.greenkeeper.io/cemremengu/fastify-oracle.svg)](https://greenkeeper.io/)
 
 This module provides access to an Oracle database connection pool via the
 [oracledb](https://npm.im/oracledb) module. It decorates the [Fastify](https://fastify.io)