* add helper to draw a ring of hazards
* refactor tests to not be internal tests
* add "hz_inner_wall" map
* add "hz_rings" map
* fix map registry
* fix: edge case bugs in drawRing
* remove println
* add "hz_columns"
* add "hz_rivers_bridges" map
* WIP: implementing spiral hazards map
* finish basic testing of 'hz_spiral'
* include first turn
* add "hz_hazards" map
* remove incorrect author
* add "hz_grow_box" map
* add "hz_expand_box" map
* add "hz_expand_scatter" map
* remove debug
* document the new "Range" method
* - use rules.RulesetError instead of generic error
- use a rules.Point for map rivers and bridgets map key
* use rules.RulesetError instead of errors.New
* provide more detail about boundar conditions
* fix documentation (max can be == min)
* add unit tests
