Remove unused test constant
Include SchemaStatements in adapter

* Fix require order
Add test geographic factories
Move #type_cast into SpatialColumn
Move adapter methods into SchemaStatements

Match upstream location of methods

[Work in Progress / Total Mess]
Whitespace, less namespacing
Remove CommonAdapterMethods module

* Move methods into MainAdapter
* Make .spatial_column_options a class method
* Move #add_spatial_column to SchemaCreation