Update ruby versions

[adfoster-r7]

Fixes the following error:

Failures:

  1) RubySMB::Dcerpc::Winreg#enum_registry_values calls #enum_key the expected number of times
     Failure/Error: expect(winreg).to have_received(:enum_value).with(subkey_handle, instance_of(Fixnum)).twice

     NameError:
       uninitialized constant Fixnum
     # ./spec/lib/ruby_smb/dcerpc/winreg_spec.rb:713:in `block (3 levels) in <top (required)>'

  2) RubySMB::Dcerpc::Winreg#enum_registry_key calls #enum_key the expected number of times
     Failure/Error: expect(winreg).to have_received(:enum_key).with(subkey_handle, instance_of(Fixnum)).twice

     NameError:
       uninitialized constant Fixnum
     # ./spec/lib/ruby_smb/dcerpc/winreg_spec.rb:634:in `block (3 levels) in <top (required)>'

[smcintyre-r7]

This is an actions specific problem. I see that the tests are running correctly now so I've gone ahead and merged this fix in. Thanks alot @adfoster-r7 !