Add each_cell! and neighbours methods (#7)

* Add format_cells and neighbours methods

* Update grid documentation

* Allow selection of just diagonal points

* Update documentation and rename method

* Update dup method

* Update changelog and version

Add single line helper (#6)

* Add single line helper

* Update version

* Update changelog

* Fix spec

Merge pull request #5 from pacso/process-each-line

Release 0.0.5

Merge pull request #4 from pacso/add-grid-class

Add Grid class

Merge pull request #3 from pacso/add-missing-dot-matrix-letters

Add missing dot matrix letters

Add DotMatrix example to readme

Merge pull request #1 from pacso/update-documentation

Add documentation