Replace now forbidden keywords public and private for snippets scope

app/controllers/snippets_controller.rb

@@ -14,7 +14,7 @@ class SnippetsController < ApplicationController
   layout 'navless'
 
   def index
-    @snippets = Snippet.public.fresh.non_expired.page(params[:page]).per(20)
+    @snippets = Snippet.is_public.fresh.non_expired.page(params[:page]).per(20)
   end
 
   def user_index

app/models/snippet.rb

@@ -34,8 +34,8 @@ class Snippet < ActiveRecord::Base
   validates :content, presence: true
 
   # Scopes
-  scope :public,  -> { where(private: false) }
-  scope :private, -> { where(private: true) }
+  scope :is_public,  -> { where(private: false) }
+  scope :is_private, -> { where(private: true) }
   scope :fresh,   -> { order("created_at DESC") }
   scope :expired, -> { where(["expires_at IS NOT NULL AND expires_at < ?", Time.current]) }
   scope :non_expired, -> { where(["expires_at IS NULL OR expires_at > ?", Time.current]) }