how to update user table in laravel 5.2

I need update My user table in Laravel 5.2. In My users table have 3 column as username,email,password. this is My edit.blade.php file

@extends('layouts.app')

@section('content')
<div class="container">
    <div class="row">
        <div class="col-md-8 col-md-offset-2">
            <div class="panel panel-default">
                <div class="panel-heading">User Profile</div>
                @include('layouts.partials.alerts')
                <div class="panel-body">
                    <form class="form-horizontal" role="form" method="POST" action="">
                        {{ csrf_field() }}

                        <div class="form-group{{ $errors->has('username') ? ' has-error' : '' }}">
                            <label for="username" class="col-md-4 control-label">Name</label>

                            <div class="col-md-6">
                                <input id="username" type="text" class="form-control" name="username" value="{{ Auth::user()->username}}">

                                @if ($errors->has('username'))
                                    <span class="help-block">
                                        <strong>{{ $errors->first('username') }}</strong>
                                    </span>
                                @endif
                            </div>
                        </div>

                        <div class="form-group{{ $errors->has('email') ? ' has-error' : '' }}">
                            <label for="email" class="col-md-4 control-label">E-Mail Address</label>

                            <div class="col-md-6">
                                <input id="email" type="email" class="form-control" name="email" value="{{ Auth::user()->email }}">

                                @if ($errors->has('email'))
                                    <span class="help-block">
                                        <strong>{{ $errors->first('email') }}</strong>
                                    </span>
                                @endif
                            </div>
                        </div>

                        <div class="form-group{{ $errors->has('password') ? ' has-error' : '' }}">
                            <label for="password" class="col-md-4 control-label">Password</label>

                            <div class="col-md-6">
                                <input id="password" type="password" class="form-control" name="password" value="{{Auth::user()->password}}">

                                @if ($errors->has('password'))
                                    <span class="help-block">
                                        <strong>{{ $errors->first('password') }}</strong>
                                    </span>
                                @endif
                            </div>
                        </div>

                        {{--   <div class="form-group{{ $errors->has('password_confirmation') ? ' has-error' : '' }}">
                            <label for="password-confirm" class="col-md-4 control-label">Confirm Password</label>

                            <div class="col-md-6">
                                <input id="password-confirm" type="password" class="form-control" name="password_confirmation">

                                @if ($errors->has('password_confirmation'))
                                    <span class="help-block">
                                        <strong>{{ $errors->first('password_confirmation') }}</strong>
                                    </span>
                                @endif
                            </div>
                        </div> --}}

                        <div class="form-group">
                            <div class="col-md-6 col-md-offset-4">
                                <button type="submit" class="btn btn-primary">
                                    <i class="fa fa-btn fa-user"></i> Update
                                </button>
                            </div>
                        </div>
                    </form>
                </div>
            </div>
        </div>
    </div>
</div>
@endsection

and this is User model

<?php

namespace App;

use Illuminate\Foundation\Auth\User as Authenticatable;

class User extends Authenticatable
{
    /**
     * The attributes that are mass assignable.
     *
     * @var array
     */
    protected $fillable = [
        'username', 'email', 'password',
    ];

    /**
     * The attributes that should be hidden for arrays.
     *
     * @var array
     */
    protected $hidden = [
        'password', 'remember_token',
    ];





public function getAvatarUrl()
{
        return "http://www.gravatar.com/avatar/" . md5(strtolower(trim($this->email))) . "?d=mm&s=40";
}

public function scopePersonal($query)
{
     return $query->where( 'id', Auth::user()->id);

}

}

I need create a colntroller file as UserController.php to update users data

can you give some help??