Revert "monkey patch of Hash"

This reverts commit 6014019e.

config/initializers/hash_patch.rb

-# We need this patch because of json format error in the CI API:
-#   IOError (not opened for reading)
-# Details: http://stackoverflow.com/questions/19808921/upgrade-to-rails-4-got-ioerror-not-opened-for-reading
-# It happens because of ActiveSupport's monkey patch of json formatters
-
-if defined?(ActiveSupport::JSON)
-  Hash.class_eval do
-    def to_json(*args)
-      super(args)
-    end
-    def as_json(*args)
-      super(args)
-    end
-  end
-end
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