feat: Move to passport for authentication (#1934)

- Added `accountProvisioner`
- Move authentication to use passport strategies
- Make authentication more pluggable
- Change language of services -> providers

closes #1120

flow-typed/globals.js

@@ -1,6 +1,7 @@
 // @flow
 declare var process: {
   exit: (code?: number) => void,
+  cwd: () => string,
   env: {
     [string]: string,
   },