Replacing deprecated os-tmpdir with tmpdir-polyfill

osenv.js

@@ -1,7 +1,7 @@
 var isWindows = process.platform === 'win32'
 var path = require('path')
 var exec = require('child_process').exec
-var osTmpdir = require('os-tmpdir')
+var osTmpdir = require('tmpdir-polyfill')
 var osHomedir = require('os-homedir')
 
 // looking up envs is a bit costly.