complete many-to-one specs, more bug fixes
associations use hidden repo finder instead of forcing user to define one

also started to add one-to-many specs
more specs for one-to-many association, bug fix
completed specs for one-to-many association
guard skips secondary adapter specs for individual integration spec file runs

Reduces amount of noise for individual spec runs. Can be easily disabled
by temporary modifying Guardfile.
add very basic many_to_many association specs
fix memoization, remove responsibilities_cache