chore: Graceful server shutdown, closes #2507

flow-typed/globals.js

@@ -3,6 +3,9 @@ declare var process: {
   exit: (code?: number) => void,
   cwd: () => string,
   argv: Array<string>,
+  on: (event: string, listener: Function) => void,
+  once: (event: string, listener: Function) => void,
+  off: (event: string, listener: Function) => void,
   env: {
     [string]: string,
   },