allow passing arbitrary options into Cell::Base, Rack and Rails constructor.
clean up test.
pass options to cell constructor in #create_cell. this could break stuff.
add test CellTest which should be authorative test.
remove Rack#create_cell, we don't need it anymore.
the ViewModel module almost works.
basic view model works. due to some stupid rails bug we can't call render multiple times, it seems.
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.
make #cell work.
more tests for the view model.
require activemodel for rails 4.
remove simpleform for tests.
use form_for instead of simpleform.
use rails 4.0 for test.
change API tests to not use simple_form but form_for as it would require a complicated bundler setup.
move view model code to separate file.
remove rbx from travis.