proper errors for existing ec2 mocks

lib/fog/aws/requests/ec2/delete_volume.rb

@@ -43,6 +43,7 @@ else
             }
           else
             response.status = 400
+            raise(Fog::Errors.status_error(200, 400, response))
           end
           response
         end

lib/fog/aws/requests/ec2/release_address.rb

@@ -38,6 +38,7 @@ else
             }
           else
             response.status = 400
+            raise(Fog::Errors.status_error(200, 400, response))
           end
           response
         end

spec/aws/ec2/delete_volume_spec.rb

@@ -13,4 +13,10 @@ describe 'EC2.create_volume' do
     actual.body['return'].should == true
   end
 
+  it "should raise a BadRequest error if volume does not exist" do
+    lambda {
+      @ec2.release_address('vol-00000000')
+    }.should raise_error(Fog::Errors::BadRequest)
+  end
+
 end

spec/aws/ec2/release_address_spec.rb

@@ -13,4 +13,10 @@ describe 'EC2.release_address' do
     actual.body['return'].should == true
   end
 
+  it "should raise a BadRequest error if address does not exist" do
+    lambda {
+      @ec2.release_address('0.0.0.0')
+    }.should raise_error(Fog::Errors::BadRequest)
+  end
+
 end