updating Rakefile and gemspec to make use of minispec
test:cleaner
test:coffeescript
test:collections
test:command
test:configuration
test:convertible
test:document
test:draft
test:entry_filter
test:excerpt
test:filters
test:front_matter_defaults
test:generated_site
test:kramdown
test:layout_reader
test:liquid_extensions
test:log_adapter
test:new_command
test:page