Log Message:
math/ruby-roo: update to 2.8.0

pkgsrc change: add "USE_LANGUAGES= # none".

##  [2.8.0] 2019-01-18
### Fixed
- Fixed inconsistent column length for CSV \ 
[375](https://github.com/roo-rb/roo/pull/375)
- Fixed formatted_value with `%` for Excelx \ 
[416](https://github.com/roo-rb/roo/pull/416)
- Improved Memory consumption and performance \ 
[434](https://github.com/roo-rb/roo/pull/434) \ 
[449](https://github.com/roo-rb/roo/pull/449) \ 
[454](https://github.com/roo-rb/roo/pull/454) \ 
[456](https://github.com/roo-rb/roo/pull/456) \ 
[458](https://github.com/roo-rb/roo/pull/458) \ 
[462](https://github.com/roo-rb/roo/pull/462) \ 
[466](https://github.com/roo-rb/roo/pull/466)
- Accept both Transitional and Strict Type for Excelx's worksheets \ 
[441](https://github.com/roo-rb/roo/pull/441)
- Fixed ruby warnings [442](https://github.com/roo-rb/roo/pull/442) \ 
[476](https://github.com/roo-rb/roo/pull/476)
- Restore support for URL as file identifier for CSV \ 
[462](https://github.com/roo-rb/roo/pull/462)
- Fixed missing location for Excelx's links \ 
[482](https://github.com/roo-rb/roo/pull/482)

### Changed / Added
- Drop support for ruby 2.2.x and lower
- Updated rubyzip version for fixing security issue. Now minimal version is 1.2.1
- Roo::Excelx::Coordinate now inherits Array \ 
[458](https://github.com/roo-rb/roo/pull/458)
- Improved Roo::HeaderRowNotFoundError exception's message \ 
[461](https://github.com/roo-rb/roo/pull/461)
- Added `empty_cell` option which by default disable allocation for \ 
Roo::Excelx::Cell::Empty [464](https://github.com/roo-rb/roo/pull/464)
- Added support for variable number of decimals for Excelx's formatted_value \ 
[387](https://github.com/roo-rb/roo/pull/387)
- Added `disable_html_injection` option to disable html injection for shared \ 
string in `Roo::Excelx` [392](https://github.com/roo-rb/roo/pull/392)
- Added image extraction for Excelx \ 
[414](https://github.com/roo-rb/roo/pull/414) \ 
[397](https://github.com/roo-rb/roo/pull/397)
- Added support for `1e6` as scientific notation for Excelx \ 
[433](https://github.com/roo-rb/roo/pull/433)
- Added support for Integer as 0 based index for Excelx's `sheet_for` \ 
[455](https://github.com/roo-rb/roo/pull/455)
- Extended `no_hyperlinks` option for non streaming Excelx methods \ 
[459](https://github.com/roo-rb/roo/pull/459)
- Added `empty_cell` option to disable Roo::Excelx::Cell::Empty allocation for \ 
Excelx [464](https://github.com/roo-rb/roo/pull/464)
- Added support for Integer with leading zero for Roo:Excelx \ 
[479](https://github.com/roo-rb/roo/pull/479)
- Refactored Excelx code [453](https://github.com/roo-rb/roo/pull/453) \ 
[477](https://github.com/roo-rb/roo/pull/477) \ 
[483](https://github.com/roo-rb/roo/pull/483) \ 
[484](https://github.com/roo-rb/roo/pull/484)

### Deprecations
- Roo::Excelx::Sheet#present_cells is deprecated \ 
[454](https://github.com/roo-rb/roo/pull/454)
- Roo::Utils.split_coordinate is deprecated \ 
[458](https://github.com/roo-rb/roo/pull/458)
- Roo::Excelx::Cell::Base#link is deprecated \ 
[457](https://github.com/roo-rb/roo/pull/457)