send common headers for axios code example

Example 1: axios defaults headers common

var instance = axios.create({
  baseURL: 'https://some-domain.com/api/',
  timeout: 1000,
  headers: {'X-Custom-Header': 'foobar'}
});

Example 2: axios defaults headers common

// GET request for remote image
axios({
  method: 'get',
  url: 'http://bit.ly/2mTM3nY',
  responseType: 'stream'
})
  .then(function(response) {
  response.data.pipe(fs.createWriteStream('ada_lovelace.jpg'))
});