Add support for extracting IdP details from metadata xml
Removed unused variables and made xpath selectors more specific
Add class AttributeValue that fixes onelogin#117
AttributeValue is a String, but `AttributeValue#values` will return
all values for that attribute.
Fixes onelogin#112 by extracting all Attribute values into single array
Require AttributeValue class in correct place
Return attributes always in reverse-XML order
Added Ruby 2.1.1 to travis
Bumped ruby 2.1.2, removed unsupported ruby-debug
Added license to the gemspec
moved back to 2.1.1, some gemfile modifications

Added a Bundler.require so that bundler will manage the dependencies.
Uses ruby-debug for ruby 1.8.*, and uses debugger for anything else.
Also, seems as if the debugger gem has yet to support ruby 2.1.2, so
moved back to ruby 2.1.1 for now.
Support for AttributeConsumingServiceIndex SAML 2.0 AuthnRequest.
add configurable validation of the Assertion ID
custom validation of the time range
Add recipient and destination validation support