v3.17.0

• If you are deploying functions, you must update the firebase-functions SDK to the latest by running "npm i --save firebase-functions@latest" inside your functions directory. This enables faster functions deployment.
• Make the environment variables $RESOURCE_DIR (e.g. projectFolder/functions/), $GCLOUD_PROJECT (e.g. projectId), and $PROJECT_DIR (e.g. projectFolder/) available in the predeploy and postdeploy hooks inside of firebase.json.
• Add "--host" flag to firebase experimental:functions:shell and firebase serve --only functions to allow specification of server host
• Add eslint to the starter template for the functions folder to catch potential bugs in functions code prior to deployment.
• Add support for hosting and functions source folders to be symbolic links.
• Fix bug where symbolic links in functions source folder produced errors.
• Fix bug where trigger parsing errors during functions deployment were only displayed as generic errors.