refactor source pixiv test

refactor pixiv download tests
refactor upload test
refactor nico seiga test
refactor twitter tests

test/unit/sources/nico_seiga_test.rb

@@ -4,17 +4,18 @@ module Sources
   class NicoSeigaTest < ActiveSupport::TestCase
     def setup
       super
+      @record = false
       setup_vcr
     end
 
     context "The source site for nico seiga" do
       setup do
-        VCR.use_cassette("source-nico-seiga-unit-test-1", :record => :once) do
+        VCR.use_cassette("sources-nico-test/1", :record => @vcr_record_option) do
           @site_1 = Sources::Site.new("http://lohas.nicoseiga.jp/o/910aecf08e542285862954017f8a33a8c32a8aec/1433298801/4937663")
           @site_1.get
         end
 
-        VCR.use_cassette("source-nico-seiga-unit-test-2", :record => :once) do
+        VCR.use_cassette("sources-nico-test/2", :record => @vcr_record_option) do
           @site_2 = Sources::Site.new("http://seiga.nicovideo.jp/seiga/im4937663")
           @site_2.get
         end