Add default behavior for both String and Object proxy option in package.json

Created by: yuanalexwu

When we fetching data from another origin we should use proxy. Normally, we set proxy option as String in pakcage.json:

{
  "proxy": "http://abc.com"
}

It works as expected.

But, if we have several apis that are cross origin.Then we should set proxy option as an Object:

{
  "proxy": {
    "/api/foo": {
      "target": "http://abc.com" 
     },
    "/api/bar": {
      "target": "http://def.com" 
     },
   }
}

It doesn't work because of the proxy request header's host does not change the origin to the target.So we still get cross origin error

We can fix it as below:

{
  "proxy": {
    "/api/foo": {
      "target": "http://abc.com" ,
      "changeOrigin": true
     },
    "/api/bar": {
      "target": "http://def.com",
      "changeOrigin": true
     },
   }
}

I think it should be a default behavior both in String and Object proxy option