chore(specs): reorganize unique lists specs
feature(unique_values_list): rename Standard and Fast unique values list to Blocking and NonBlocking respectively
feature(unique_values_list): introduce has_value? method
feature(unique_values_list): introduced a list of unique values to expiry of the members
Merge pull request #8 from Napolskih/experimental2

feature(unique_values_list): introduced a list of unique values to expiry of the members