Add explicit implementation of Config::Options#as_json

Before, `Config::Options#as_json` was explicitly set, but the class
included the `Enumerable` module. So, if you were using ActiveSupport
Core Extensions, then the definition of `#as_json` for Enumerable was
invoked, which would represent the `Config::Options` as a Array of
key-value pairs instead of a Hash.

This changes brings `#as_json` in line with the output we get from
`to_json`: essentially, calling these methods on an instance of
`Config::Options` behaves the same as if they were called instead on
the hash returned by `to_hash`.

CHANGELOG.md

@@ -6,6 +6,7 @@
 
 * Added alias to_h for to_hash ([#277](https://github.com/railsconfig/config/issues/277))
 * Prevent unnecessary doubled loading of environment variables ([#291](https://github.com/rubyconfig/config/pull/291))
+* Return `Hash` from `Config::Options#as_json` instead of `Array` of pairs when using ActiveSupport Core Extensions ([#292](https://github.com/rubyconfig/config/pull/292))
 
 ### Changes
 

lib/config/options.rb

@@ -129,6 +129,10 @@ def to_json(*args)
       to_hash.to_json(*args)
     end
 
+    def as_json(options = nil)
+      to_hash.as_json(options)
+    end
+
     def merge!(hash)
       current = to_hash
       DeepMerge.deep_merge!(

spec/options_spec.rb

@@ -224,4 +224,10 @@
 
   end
 
+  context 'when calling #as_json' do
+    it 'should return a Hash of the keys and values' do
+      options = Config::Options.new(foo: :bar)
+      expect(options.as_json).to eq({ 'foo' => 'bar' })
+    end
+  end
 end