add BassistCell#provoke.
make Builder#create_cell_for available as (the new authorative) Builder#cell_for.
implement #cell (aka #cell_for) as a controller method.
restructure Rails IntegrationTest.
add #cell (aliased #cell_for) to ActionController and ActionView which will return a cell instance. this might become the new prefered API for working with cells, especially with the new view model concept.