fix a name of vital module

:TweetVimHomeTimeline などのタイムライン取得時に下記のエラーが出ることに気づきました

    Error detected while processing function <SNR>92_import..<SNR>92__import:
    line   13:
    E605: Exception not caught: vital: module not found: Web.Html

vital のモジュール名が間違っているっぽかったので修正しました。
Merge pull request #27 from rhysd/fix/vital_module_name

fix a name of vital module
Merge branch 'dev'
bump up version
added around action
improved around action
changed count
improved around action
break if no tweets
Fix README
Merge pull request #28 from camelmasa/master

Fix README
Fix README
added new option: g:tweetvim_align_right
not make newline
unnecessary + 0
fix number_width
fixed for g:tweetvim_display_icon=1
Improve g:tweetvim_display_icon calculation
updated vital
fixed add_member_to_list