Log Message:
Update to 0.28

Upstream changes:
0.28    2015-01-22
     - Convert Changes to CPAN::Changes and add t/cpan-changes.t .

0.27    2015-01-22
    - Cache parsed range patterns.
        - Pull Request from Kosuke Asami (co-me). Thanks!
            - https://github.com/shlomif/String-Random/pull/1
    - Clean up the code according to perlcritic.
        - Pull Request from Lance Brown. Thanks!
            - https://github.com/shlomif/String-Random/pull/2
    - Add rand_gen parameter to new to specify a custom random generator.
        - Pull Request from Lance Brown. Thanks!
            - https://github.com/shlomif/String-Random/pull/3