chore: inits RSpec
fix(spec_helper.rb): requires the library
feat: implements Configuration class
improve(Extensions): implements `configuration`, `configure` methods
improve(Configuration): adds `base_path`, `css_path` keys
feat: implements AssetManager module
improve(AssetManager): implements `path_to` method
chore(.rspec): sets Ruby warnings off
chore(.gitignore): ignores Sublime Text project files
fix(gemspec): adds missing `fakefs` development dependency
feat: implements Functions module
improve(Functions/asset-url): keeps hash and query params
improve(Functions/asset-url): implements cache buster
chore(Rakefile): includes `spec` task
chore: inits Guard
improve(Functions/asset-url): allows path to contain whitespace
style(spec): converts `describe` titles to the Better Spec style
feat: introduces SimpleCov
chore(spec): removes explicit spec_helper requirement
chore(spec/spec_helper.rb): removes default comments