Remove the use of predicates from the docs

Author: chrisroos

doc/smart-answer-flows.md

@@ -107,19 +107,6 @@ next_node(permitted: permitted_next_nodes) do |response|
 end
 ```
 
-#### DEPRECATED: Using predicates
-
-This is the same example from above expressed using predicates:
-
-```ruby
-next_node_if(:green, responded_with('green')) )
-next_node(:red)
-```
-
-The `responded_with` function actually returns a [predicate](http://en.wikipedia.org/wiki/Predicate_%28mathematical_logic%29) which will be invoked during processing. If the predicate returns `true` then the `:green` node will be next, otherwise the next rule will be evaluated. In this case the next rule says `:red` is the next node with no condition.
-
-See [Smart Answer predicates](smart-answers-predicates.md) for more detailed information about this style.
-
 ### Storing data for later use
 
 You can use the `precalculate`, `next_node_calculation`, `save_input_as` and `calculate` methods to store data for later use.