fix(windows): revert writing all possible cases of PATH variables (#22)

Fixes: #20

Author: JimiC

index.js

@@ -122,9 +122,6 @@ function lifecycle_ (pkg, stage, wd, opts, env, cb) {
 
   if (env[PATH]) pathArr.push(env[PATH])
   env[PATH] = pathArr.join(process.platform === 'win32' ? ';' : ':')
-  if (process.platform === 'win32') {
-    env.path = env.PATH = env.Path = env[PATH]
-  }
 
   var packageLifecycle = pkg.scripts && pkg.scripts.hasOwnProperty(stage)