test environment
change rspec style to expect and use vcr
move Env to XvideosHelper::ENV
use mechanize
change api and combine crawler with client
split crawler in movie and tag
Crawler shortcut methods move to class method
add Movie#size
fix spec
change the name
fix spec
move some methods to crawler
add Crawler::Tag spec and fix
change movie attributes name
change tag attributes name
update doc
add movies command
remove ENV
update doc
fix command