AssetCategory model improvements

Indentation fixes
method_missing better implementation. now it will throw NoMethodError exception {category_name}_category method call is not valid.

use of .where instead of find
dummy app for gluttonberg
specs setup with latest rspec gem
test_files path is fixed and also wrote latest version number for each dependency in comments
Rakefile fixes for rspec
removed commented code from rake file
Assettype, asset collection and asset category specs