Add basic playlists management

* Index of playlists
* Create a new playlist
* Basic playlist model with mandatory name

app/controllers/playlists_controller.rb

@@ -0,0 +1,18 @@
+class PlaylistsController < ApplicationController
+  def index
+    @playlists = Playlist.all
+  end
+
+  def new
+    @playlist = Playlist.new
+  end
+
+  def create
+    @playlist = Playlist.new params[:playlist]
+    if @playlist.save
+      redirect_to :action => 'index'
+    else
+      render :action => 'new'
+    end
+  end
+end

app/models/playlist.rb

@@ -0,0 +1,3 @@
+class Playlist < ActiveRecord::Base
+  validates_presence_of :name
+end

app/views/playlists/index.html.haml

@@ -0,0 +1,4 @@
+= link_to 'Create playlist', new_playlist_path
+%ul
+  - @playlists.each do |p|
+    %li= p.name

app/views/playlists/new.html.haml

@@ -0,0 +1,4 @@
+= form_for @playlist do |f|
+  = f.label :name
+  = f.text_field :name
+  = f.submit 'Create'