Trying to Use entity framework core for database first approach in class library with the existing database

Using Aps.Net core 1.0.1, Entityframework core, angular2.0 and typescript having existing database.

Trying to create entity framework core database first for class library using the existing database

My project.json looks like this for my class library

{
  "version": "1.0.0-*",

  "buildOptions": {
    "emitEntryPoint": true
  },

  "frameworks": {
    "netcoreapp1.0": {
      "dependencies": {
        "Microsoft.NETCore.App": {
          "version": "1.0.1",
          "type": "platform"
        }
      }
    }
  },

  "dependencies": {
    "Microsoft.EntityFrameworkCore.SqlServer": "1.0.1",
    "Microsoft.EntityFrameworkCore.SqlServer.Design": {
      "version": "1.0.1",
      "type": "build"
    },
    "Microsoft.EntityFrameworkCore.Tools": {
      "version": "1.0.0-preview2-final",
      "type": "build"
    }
  },

  "tools": {
    "Microsoft.EntityFrameworkCore.Tools": "1.0.0-preview2-final"
  }
}