Stop overriding #class

ARHP has been overriding `#class` so that `connection.class.class_eval`
can work. That makes it _very_ hard to debug ARHP issues because you're
never quite sure what object you're working with.

I've changed it so that we now raise an exception if you try to call
`.class_eval` on the `ConnectionProxy` class but implements a
`._class_eval` method that will allow the typical `class_eval` behavior
if someone _really_ needs to.

Author: HeyNonster

lib/active_record_host_pool/connection_proxy.rb

@@ -6,6 +6,16 @@
 # for each call to the connection.  upon executing a statement, the connection will switch to that database.
 module ActiveRecordHostPool
   class ConnectionProxy < Delegator
+    class << self
+      def class_eval
+        raise "You probably want to call .class_eval on the ActiveRecord connection adapter and not on ActiveRecordHostPool's connection proxy. Use ._class_eval if you _really_ know what you're doing."
+      end
+
+      def _class_eval(...)
+        method(:class_eval).super_method.call(...)
+      end
+    end
+
     attr_reader :database
     def initialize(cx, database)
       super(cx)
@@ -26,11 +36,6 @@ def unproxied
       @cx
     end
 
-    # this is bad.  I know.  but it allows folks who class_eval on connection.class to do so
-    def class
-      @cx.class
-    end
-
     def expects(*args)
       @cx.send(:expects, *args)
     end