Update to 0.56
Update BUILD_DEPENDS

Upstream changes:
0.56      2013-02-15 13:13:18 PST-0800
- depend on newest Path::Tiny, to regain 5.8.x compatibility (gone since
  v0.52)

0.55      2013-02-12 10:02:55 PST-0800
- fix broken tests on win32 with file comparisons

0.54      2013-02-09 16:25:32 PST-0800
- fix broken tests on win32 with file comparisons
- allow configfiles called "0"
- support more mechanisms for overriding default configfile
- when using in conjunction with MooseX::ConfigFromFile, configfile value now
  properly passed to new()

0.53      2013-02-05 09:59:00 PST-0800
- properly indicate optional dependency in tests using
  MooseX::ConfigFromFile

0.52      2013-02-02 19:01:25 PST-0800
- tests converted from using Path::Class to Path::Tiny

0.51      2013-01-27 09:38:11 PST-0800
- missing test prereqs now declared (thanks for the automated reports, David
  Cantrell!)

0.50      2012-12-27 00:20:56 PST-0800
- unbreak Catalyst::Runtime tests (etc) by keeping _getopt_full_usage in the
  callstack. (RT#82249)

0.49      2012-12-26 10:13:41 PST-0800
- silence a warning in tests if the user does not have YAML::XS installed
  (thanks for the report, Getty!)
- fix off-by-one issues in test plans if optional requirements are not met

0.48      2012-12-23 18:08:04 PST-0800
- documentation and tests amended to prefer usage of 'trait' over 'metaclass'
  as much as possible
- print_usage_text() exposed as a public method, to make it easier for
  consuming classes to modify the behaviour when usage text is printed

(wen)