Adds spec for issue with memoization and dynamic methods

[alxberardi]

Hi @dkubb ,

I think I might have found an issue with memoization.

Apparently, when memoizing a method which initialises objects that define methods dynamically, the dynamic methods on the object are no longer public.

Please see the spec I added to replicate the problem.

When running the spec, this is the output I get (stripped of non relevant lines):

bundle exec rspec spec/unit/adamantium/dynamic_methods_memoize_spec.rb 

FF...

Failures:

  1) Adamantium memoizing methods that initialize objects with dynamically defined methods a composed instance its composed should respond to #test
     Failure/Error: it      { is_expected.to respond_to(:test) }
       expected #<Component:0x007f85f399b5a8 @test=true> to respond to :test
     # ./spec/unit/adamantium/dynamic_methods_memoize_spec.rb:47:in `block (4 levels) in <top (required)>'
     # ./vendor/ruby/2.2.0/bundler/gems/devtools-8d492930b9a5/lib/devtools/project/initializer/rspec.rb:48:in `block in enable_unit_test_timeout'

  2) Adamantium memoizing methods that initialize objects with dynamically defined methods a composed instance its composed 
     Failure/Error: specify { expect(subject.test).to eq true }

     NoMethodError:
       private method `test' called for #<Component:0x007f85f1283f88 @test=true>
     # ./spec/unit/adamantium/dynamic_methods_memoize_spec.rb:48:in `block (4 levels) in <top (required)>'
     # ./vendor/ruby/2.2.0/bundler/gems/devtools-8d492930b9a5/lib/devtools/project/initializer/rspec.rb:48:in `block in enable_unit_test_timeout'

Finished in 0.01913 seconds (files took 0.46045 seconds to load)
5 examples, 2 failures

Failed examples:

rspec ./spec/unit/adamantium/dynamic_methods_memoize_spec.rb:47 # Adamantium memoizing methods that initialize objects with dynamically defined methods a composed instance its composed should respond to #test
rspec ./spec/unit/adamantium/dynamic_methods_memoize_spec.rb:48 # Adamantium memoizing methods that initialize objects with dynamically defined methods a composed instance its composed 

I apologise for not having provided a solution, unfortunately I do not have the time to investigate the issue any further at this moment, but I hope that the spec I provided might help you investigate the issue for future releases.