Implement IdpMetadataParser#parse_to_hash

[tosch]

…and IdpMetadataParser#parse_remote_to_hash.

Having the parsed metadata as Hash may be useful for configuring omniauth-saml, for instance. See omniauth/omniauth-saml#135

[tosch]

I briefly considered changing the interface of the IdpMetadataParser even further:

parser = OneLogin::RubySaml::IdpMetadataParser::FromString.new(xml_string, parse_options)
# or
parser = OneLogin::RubySaml::IdpMetadataParser::FromURL.new(url, parse_options)
# or maybe even
parser = OneLogin::RubySaml::IdpMetadataParser::FromFile.new(url, parse_options)

# maybe with some helper class methods:
parser = OneLogin::RubySaml::IdpMetadataParser.new_for_string(xml_string, parse_options)
# etc.

parser.to_settings # returns OneLogin::RubySaml::Settings
parser.to_hash # returns an Hash

while this would be an imho cleaner interface (and avoids the side effects of setting instance variables in the current #parse method), I did not implement that as it would break the current API. If you want to see that in a future major release — I'm happy to contribute that.

[pitbulk]

Nice work,

related to the rename that you mentioned here, rest of toolkits already uses the same name convention, so at the end is complex to apply a change like that.

Reviewing your PR, I noticed that we renamed options by parse_options.

I think we need to rename it back to options, since it can contains parse_options, but also a settings object.
And update the parameter description that currently only mention the settings stuff:

@param options [Hash] :settings to provide the OneLogin::RubySaml::Settings object or an hash for Settings overrides

What do you think?

[tosch]

@pitbulk I've updated the PR accordingly. I was not sure about all the @options, so please review those descriptions carefully.

[pitbulk]

I think now is perfect