Added support for building an API from a file.
Added support for building an API from a file.

stems/google-api-nodejs-client,sqrrrl/google-api-nodejs-client,stems/google-api-nodejs-client,sqrrrl/google-api-nodejs-client,googleapis/google-api-nodejs-client,chitsuhein/google-api-nodejs-client,sqrrrl/google-api-nodejs-client,sqrrrl/google-api-nodejs-client,googleapis/google-api-nodejs-client,stems/google-api-nodejs-client,stems/google-api-nodejs-client,sqrrrl/google-api-nodejs-client,stems/google-api-nodejs-client,googleapis/google-api-nodejs-client