Ensure Kernel.raise remains private after patch

Kernel.raise is originally private, but define_method(:raise) creates a
method that is public. Use `private :raise` to make the redefined method
private to be consistent with default Ruby behavior.

Fixes #350.

Author: mattbrictson

CHANGELOG.md

@@ -5,6 +5,7 @@
 * Custom Spring commands that implement `#binstub_prelude` will have that
   snippet of code inserted into generated binstubs just after Spring is
   set up. #329 - @merhard
+* Change monkey-patched `Kernel.raise` from public to private (to match default Ruby behavior) #351 - @mattbrictson
 
 ## 1.1.3
 

lib/spring/application.rb

@@ -270,6 +270,7 @@ def shush_backtraces
             end
           end
         end
+        private :raise
       end
     end
 

test/acceptance/app_test.rb

@@ -350,4 +350,9 @@ def binstub_prelude
     assert_success %(bin/rails runner 'p ENV["OMG"]'), stdout: "2"
     assert_success %(bin/rails runner 'p ENV.key?("FOO")'), stdout: "false"
   end
+
+  test "Kernel.raise remains private" do
+    expr = "p Kernel.private_instance_methods.include?(:raise)"
+    assert_success %(bin/rails runner '#{expr}'), stdout: "true"
+  end
 end