字數判定改用mb_strlen + html5 input&textarea maxlength
Merge pull request #17 from touhonoob/mb_strlen

- CHG: 改用 mb_strlen 計算字數 (Thanks touhonoob)
- CHG: 加上 HTML5 input, textarea maxlength 屬性 (Thanks touhonoob)
introduce Travis-CI
added selenium tests