fog/fog-core — pull request #90 by tnaoto (2014-10-09 10:28:50+00:00)
Title: FIX: Output of the ERROR message of const_get method is not enough.

This PR is fix my PR #54.

If initializer of Fog::Identity::ProviderName in line 17 raises an exception,
the exception is caught by `rescue` block and eventually `NameError` will be raised in line 19.
This hides the internal exception and makes debugging hard.

```ruby
class Fog::Identity::ProviderName
class Real
def initialize
raise "error"
end
end
end

# No definition of Fog::ProviderName::Identity
```