- the introduced actual password should be equal to the actual password of the user (users table has a column "password" on db)
- the new_password and new_password_confirm should be equal
- the actual_password and new_password should be different

public function updatePassword(Request $request){
            $this->validate($request, [
            'actual_password' => 'required|string|min:6|confirmed',
            'new_password' => 'required|string|min:6',
            'new_password_confirm' => 'required|string|min:6|same:new_password',
            ]);

            $user = Auth::user();
            $user->password = bcrypt($request->new_password);
            $user->save();

            Session::flash('success', 'updated.');

            return redirect()->back();
        }

<form method="post" action="{{route('user.updatePassword')}}" class="clearfix">
     {{csrf_field()}}
       <div>
            <label>New Password</label>
            <input type="password" class="form-control" name="actual_password" id="actual_password" placeholder="">
        </div>
        <div>
            <label for="new_password">New Password</label>
            <input type="password" class="form-control" name="new_password" id="new_password" placeholder="">
        </div>
        <div>
            <label>Confirm password</label>
            <input type="password" name="new_password_confirm" class="form-control" id="new_password_confirm" placeholder="">
        </div>
        <div class="form-group">
            <input type="submit" value="Update password"/>
        </div>
    </form>