Add tests for Configuration#add_default_collections
Add tests for Configuration#add_default_collections

ryanshaw/jekyll,jekyll/jekyll,gencer/jekyll,ryanshaw/jekyll,derekgottlieb/jekyll,jaybe-jekyll/jekyll,yhironaka/yhironaka.github.io,tomjohnson1492/jekyll,stomar/jekyll,ZDroid/jekyll,rlugojr/jekyll,fulldecent/jekyll,Strangehill/jekyll,derekgottlieb/jekyll,ryanshaw/jekyll,Strangehill/jekyll,jaybe-jekyll/jekyll,ZDroid/jekyll,floydpraveen/jekyll,pmarsceill/jekyll,x-way/jekyll,chrisfinazzo/jekyll,rlugojr/jekyll,rlugojr/jekyll,fulldecent/jekyll,jeffkole/jekyll,floydpraveen/jekyll,tillgrallert/jekyll,rasa2011/rasa2011.github.io,jeffkole/jekyll,getandpost/jekyll.github.io,jekyll/jekyll,rlugojr/jekyll,stomar/jekyll,darwin/jekyll,tomjohnson1492/jekyll,alfredxing/jekyll,gencer/jekyll,alex-kovac/jekyll,darwin/jekyll,x-way/jekyll,stomar/jekyll,chrisfinazzo/jekyll,jaybe-jekyll/jekyll,ZDroid/jekyll,Strangehill/jekyll,fulldecent/jekyll,xiebinhqy/jklly_china,tillgrallert/jekyll,pmarsceill/jekyll,jekyll/jekyll,nasht00/jekyll,alfredxing/jekyll,stomar/jekyll,jeffkole/jekyll,noikiy/jekyll,chrisfinazzo/jekyll,darwin/jekyll,jekyll/jekyll,noikiy/jekyll,nasht00/jekyll,tillgrallert/jekyll,gencer/jekyll,xiebinhqy/jklly_china,pmarsceill/jekyll,getandpost/jekyll.github.io,alex-kovac/jekyll,Strangehill/jekyll,noikiy/jekyll,jeffkole/jekyll,gencer/jekyll,pmarsceill/jekyll,nasht00/jekyll,derekgottlieb/jekyll,xiebinhqy/jklly_china,xcatliu/jekyllcn,alex-kovac/jekyll,gencer/jekyll,floydpraveen/jekyll,floydpraveen/jekyll,noikiy/jekyll,rasa2011/rasa2011.github.io,tillgrallert/jekyll,xcatliu/jekyllcn,getandpost/jekyll.github.io,fulldecent/jekyll,xcatliu/jekyllcn,alex-kovac/jekyll,xiebinhqy/jklly_china,ryanshaw/jekyll,Strangehill/jekyll,jaybe-jekyll/jekyll,alfredxing/jekyll,darwin/jekyll,x-way/jekyll,tillgrallert/jekyll,alfredxing/jekyll,derekgottlieb/jekyll,x-way/jekyll,rasa2011/rasa2011.github.io,tomjohnson1492/jekyll,nasht00/jekyll,tomjohnson1492/jekyll,xcatliu/jekyllcn,chrisfinazzo/jekyll,alex-kovac/jekyll,tomjohnson1492/jekyll