Log Message:
Update ruby-locale to 2.1.0.

## 2.1.0: 2013-12-15

### Fixes

  * Fixed a bug that memoization key hash collision on armv7hl.
    Memoization feature is removed for this fix. If you get
    performance issue. Please report it. We will solve the issue.
    [GitHub#3] [Reported by mtasaka]

### Thanks

  * mtasaka

## 2.0.9: 2013-09-20

Locale handling fix release.

### Improvements

  * Added license metadata to gem package.
    [GitHub#1] [Suggested by jordimassaguerpla]

### Fixes

  * Added missing .yardopts file.
  * Fixed a bug that wrong environment value is used.
    [Debian:#520181][Debian:#690572][GitHub#2]
    [Reported by Stefano Zacchiroli][Reported by Hleb Valoshka]

### Thanks

  * jordimassaguerpla
  * Stefano Zacchiroli
  * Hleb Valoshka