Merge branch 'release/0.2' into develop

* release/0.2:
  bump 0.2
[requires.io] dependency update
Merge pull request #14 from saxix/requires-io-develop

[requires.io] dependency update on develop branch
- adds `render_xls` to `DateWidget`
- adds `format` parameter to `with_widget` to invoke specific widget renderer
Merge pull request #16 from mrc75/feature/xls-formats

fixes Date format on excel reports
bump 0.3
Merge branch 'release/0.3'

* release/0.3:
  bump 0.3
  - adds `render_xls` to `DateWidget` - adds `format` parameter to `with_widget` to invoke specific widget renderer
  [requires.io] dependency update