Version 2.0

Big refactor, turned out basically the same.

  - No more global error states (yay!)
  - Added `Ficus.load` so configs can be read from a string (Issue #6)
  - basic type checking (`:number`, `:string`, `:boolean`) (Issue #11)
  - full feature parity with 1.0
I think you can leave out the "else nil" block if you want to - should return nil if no condition matches anyway.

Le voila:
```
[2] pry(main)> if false
[2] pry(main)*   'hello'
[2] pry(main)* end
=> nil
```