title: Paperclip::Errors::MissingRequiredValidatorError with Rails 4
body: <p>I'm getting this error when I try to upload using paperclip with my rails blogging app.
  Not sure what it is referring to when it says "MissingRequiredValidatorError"
  I thought that by updating post_params and giving it :image it would be fine, as both create and update use post_params</p>
  
  <pre><code>Paperclip::Errors::MissingRequiredValidatorError in PostsController#create
  Paperclip::Errors::MissingRequiredValidatorError
  
  Extracted source (around line #30):
  
  def create
    @post = Post.new(post_params)
  </code></pre>
  
  <p>This is my posts_controller.rb      </p>
  
  <pre><code>def update
    @post = Post.find(params[:id])
  
    if @post.update(post_params)
      redirect_to action: :show, id: @post.id
    else
      render 'edit'
    end
  end
  
  def new
    @post = Post.new
  end
  
  def create
    @post = Post.new(post_params)
  
    if @post.save
      redirect_to action: :show, id: @post.id
    else
      render 'new'
    end
  end
  #...
  
  private
  
  def post_params
    params.require(:post).permit(:title, :text, :image)
  end    
  </code></pre>
  
  <p>and this is my posts helper </p>
  
  <pre><code>module PostsHelper
    def post_params
      params.require(:post).permit(:title, :body, :tag_list, :image)
    end
  end
  </code></pre>
  
  <p>Please let me know if I can supplement extra material to help you help me.</p>