fix(getNpmToken): fix flow error

Author: jedwards1211

.gitignore

@@ -4,6 +4,8 @@ node_modules
 lib
 es
 .eslintcache
-/*.js
-/*.js.flow
+*.js
+*.js.flow
+!/src/**/*.js
+!/test/**/*.js
 !/.babelrc.js

src/getNpmToken.js

@@ -1,7 +1,7 @@
 // @flow
 
 import os from 'os'
-import fs from 'fs-extra'
+import * as fs from 'fs-extra'
 import once from './util/once'
 
 const getNpmToken = once(