[WIP] Upgrade equalizer and use adamantium from master

This branch upgrades equalizer to 0.0.9 and uses adamatium from master which no longer has the issue described in #51 

There's 27 failing tests related to changed implementation of `#hash` method in equalizer (IIRC). Personally I'd vote for removing those tests altogether since it is a feature coming from Equalizer gem and it is tested there. I don't see any reason why this should be tested here (again, those tests check implementation details, very little value). Alternatively we could have tests for `#eql?` instead of `#hash` which would test behavior and not implementation. Yes, I've become a huge BDD fan lately ;)

Another problem is with adamantium from master, even though #51 is no longer a problem with edge adamantium there's a lot of failures ending up with an error like that:

```
 144) Axiom::Function::Predicate::LessThan#inverse right
   Failure/Error: subject { object.inverse }
   ArgumentError:
     wrong number of arguments (2 for 1)
   # /Users/solnic/.gem/ruby/1.9.3/gems/memoizable-0.4.0/lib/memoizable/instance_methods.rb:32:in `memoize'
   # ./lib/axiom/function/binary.rb:87:in `inverse'
  ...
```

I guess some public interface in adamantium changed and axiom should be updated. I can do that but I need some guidance.