v3.17.5

• Breaking: If you are using firebase-tools to deploy functions written with firebase-functions SDK, previously undocumented fields `apiKey` and `authDomain` have been removed from `functions.config()`. Please use `firebase functions:config:set` to store any API keys needed by your application.
• If you are emulating functions using firebase serve --only functions or firebase experimental:functions:shell, you must update Node to v6.11.5 or higher.
• Support emulation of nested functions, where a function is nested inside an object being exported by index.js.
• Increased PBKDF2_SHA256 round limit to 120000 for firebase auth:import
• Fixed installation issues related to grpc, by removing it as a dependency.
• Fixed the template for functions/package.json for TypeScript projects to refer to the correct tslint configuration file.
• Fixed bugs in functions lifecycle hooks for Windows users, caused by environment variables with $ and scripts with '.'.
• Fixed issue encountered in functions lifecycle hooks when the directory has a space.
• Fixed functions deployment errors due to outdated version of tar.