Allow count removal by setting the value to nil

[#94]

lib/ice_cube/validated_rule.rb

@@ -93,7 +93,11 @@ def validations_for(key)
 
     # Fully replace validations
     def replace_validations_for(key, arr)
-      @validations[key] = arr
+      if arr.nil?
+        @validations.delete(key)
+      else
+        @validations[key] = arr
+      end
     end
 
     # Remove the specified base validations

spec/examples/ice_cube_spec.rb

@@ -790,6 +790,18 @@
     rule.occurrence_count.should == 5
   end
 
+  it 'should be able to remove a count validation from a rule' do
+    rule = IceCube::Rule.daily.count(5)
+    rule.occurrence_count.should == 5
+    rule.count nil
+    rule.occurrence_count.should raise_error
+  end
 
-end
+  it 'should be able to remove a count validation from a rule' do
+    rule = IceCube::Rule.daily.count(5)
+    rule.to_hash[:count].should == 5
+    rule.count nil
+    rule.to_hash[:count].should be_nil
+  end
 
+end