replace instance variables with let syntax
in card a checklist specs. Fixes incompatability
between ruby-2.0 and activemodel dependency which
call #initialize_dup as a public method
Merge pull request #41 from rossta/ruby_head_compatability

Make specs compatible with ruby-head
README update
Merge remote-tracking branch 'upstream/master' into configurable_client

Conflicts:
	spec/card_spec.rb
	spec/checklist_spec.rb