Fastify-cli compatibility

[pc3b3r]

Describe the bug Using https://github.com/fastify/fastify-cli generator, the server is starting with the start script on package.json and the app is loaded as a plugin (app.js). APM should be on the top of the Fastify module but, considering it's a dependency, it's not possible to add it. Putting it on the top of the plugin (app.js) doesn't work.

To Reproduce

Steps to reproduce the behavior:

1. Use this config (on app.js)

require('elastic-apm-node').start({
  //MY PARAMS
  logLevel: 'trace'
})

2. Then call 'npm start'
3. See no shimming logs

Expected behavior

Start APM agent for Fastify

Environment (please complete the following information)

• OS: [e.g. Linux]
• Node.js version: 12.13.1
• APM Server version: 7.6.1
• Agent version: Fastify

How are you starting the agent? (please tick one of the boxes)

• [X] Calling agent.start() directly (e.g. require('elastic-apm-node').start(...))
• [ ] Requiring elastic-apm-node/start from within the source code
• [ ] Starting node with -r elastic-apm-node/start