added script/ucrawl-tweet

 - added ucrawl-tweet. it's still incomplete.
   - it will be the script to crawl and store
     tweets into your database.

 - muted warnings 'experimental::smartmatch.'
   so, this module supports v5.18.

 - added dependencies. newly requires:
    - experimental
    - namespace::clean
    - Encode::Locale
    - Smart::Options
    - Net::Twitter::Lite

 - added badge of travis ci.

 - fixed tests.