Support react-admin for Loopback 3.0.

1. Run npm install --save loopback-component-react-admin
2. Set the module in your component-config.json (loopback server endpoint).

  "loopback-component-react-admin": {
    "pattern": [
      "*.find"
    ],
    // More options here
  }

We recommend to use yarn instead of npm:

1. yarn add loopback-component-react-admin
2. Set the module in your component-config.json

  "loopback-component-react-admin": {
    "pattern": [
      "*.find"
    ],
    // More options here
  }

Method patterns that Content-Range header will be added.

Accepted patterns: See https://loopback.io/doc/en/lb3/Remote-hooks.html#wildcards.

Default value: [ "*.find" ], which auto added to find method of all models.

This is the updated version of loopback3-xTotalCount and aor-loopback. On client side (mean react-admin), we don't need to change anything, just use ra-data-simple-rest as usual.