Remove ExampleBase

Pending/skip functionality will be merged into Example or extend from 
it.

src/spectator/example.cr

@@ -1,12 +1,12 @@
 require "./context_delegate"
-require "./example_base"
 require "./example_group"
+require "./example_node"
 require "./result"
 require "./source"
 
 module Spectator
   # Standard example that runs a test case.
-  class Example < ExampleBase
+  class Example < ExampleNode
     # Indicates whether the example already ran.
     getter? finished : Bool = false
 
@@ -30,5 +30,10 @@ module Spectator
     def run : Result
       raise NotImplementedError.new("#run")
     end
+
+    # Exposes information about the example useful for debugging.
+    def inspect(io)
+      raise NotImplementedError.new("#inspect")
+    end
   end
 end

src/spectator/example_base.cr

@@ -1,23 +0,0 @@
-require "./example_node"
-require "./result"
-
-module Spectator
-  # Common base type for all examples.
-  abstract class ExampleBase < ExampleNode
-    # Retrieves the result of the last time the example ran.
-    # This will be nil if the example hasn't run,
-    # and should not be nil if it has.
-    abstract def result? : Result?
-
-    # Retrieves the result of the last time the example ran.
-    # Raises an error if the example hasn't run.
-    def result : Result
-      result? || raise(NilAssertionError("Example has no result"))
-    end
-
-    # Exposes information about the example useful for debugging.
-    def inspect(io)
-      raise NotImplementedError.new("#inspect")
-    end
-  end
-end