Pysaml2

- Accept and forward sign and digest alg information when creating a metadata string
- Fix tests to comply with latest xmlschema

- Add schemas for eIDAS extensions, elements and attributes
- Add the voPerson v2 attributes mappings; see [reference](https://github.com/voperson/voperson/tree/2.0.0)
- Add the `registration_info_typ` method on `saml2.mdstore.MetadataStore` to get the registration information from an `EntityDescriptor` services
- Allow exceptions to convey the SAML `StatusCode` in an error response
- Fix typo on method name under `saml2.mdstore.MetadataStore`; from `sbibmd_scopes` to `shibmd_scopes`
- Add partial support for `xs:date` `AttributeValue` type
- Fallback to `xs:string` as the type of the `AttributeValue` text node
- Fallback to the authn context class declaration to set the authn context class reference
- Αdd configuration option `http_client_timeout` to set a timeout on the HTTP calls by the httpbase module
- Load certificates using cryptography and support certificate chains
- Remove deprecated cryptography backend param
- Fix assertion policy filter: Fallback to match a known attribute or return its name
- examples: Allow multiple attributes to be returned by the idp
- tests: Minor cleanups
- docs: Reference python2 compatible fork
- misc: add pepy badges on the README file

- fix assertion policy filter to try to resolve the local_name using the friendly name if it failed with the name_format
- reload metadata in-place to avoid memory leak
- tests: Restrict pymongo to v3
- docs: highlight installation command

- Process and verify the metadata signature for EntitiesDescriptor and EntityDescriptor
- Fix client to be able to retry creating an AuthnRequest with a different binding
- Allow requested_authn_context to be an object
- AttributeValues are optional; allow Attributes to not have values
- Update SWAMID entity category to support https://myacademicid.org/entity-categories/esi
- Fix signing for requests with the SOAP binding
- tests: new test case for signed SOAP LogoutRequests
- docs: document the metadata node_name option for the remote source
- examples: align with latest updates
- deps: declare setuptools as a requirement for processing the package version
- build: add python 3.9 and 3.10 to classifiers
- misc: linter fixes

The following **breaking changes** are not reflected in the version by mistake:

- the method `saml2.mdstore.Metadata::certs` used to return a list of certificate data - `List[str]`.
This method has now changed to return a list of tuples - `List[Tuple[str, str]]` - where the first item in the tuple holds the key name, and the second the certificate data.

---

Changes:

- Fix signature verification for the redirect binding for AuthnRequest and
LogoutRequest.
- Include encryption KeyName in encrypted assertions.
- Add "reason" field in invalid signature errors due to invalid document format.
- New SP configuration option requested_authn_context to set the preferred
RequestedAuthnContext class reference.
- Add support for metadata refresh by adding a metadata_reload method into saml2.Entity.
This method is to be externally invoked, and to receive the same metadata
configuration as what was passed under the metadata key to saml2.Config. The method
loads a new metadata configuration and swaps it in (replacing the references across
several objects that hold a metadata reference).
- Fix SessionIndex resolution during logout.
- Fix AuthnResponse::get_subject to be able to decrypt a NameID with the given keys.
- Refactor AuthnResponse::authn_info to consider DeclRef equivalent to ClassRef.
- Ensure creation of multiple ePTIDs is handled correctly.
- Improve signature checks by ensuring the Object element is absent, enforcing allowed
transform aglorithms, enforcing allowed canonicalization methods and requiring the
enveloped-signature transform to be present.
- mdstore: Make unknown metadata extensions available through the internal metadata.
- mdstore: Fix the exception handler of the InMemoryMetaData object.
- mdstore: Fix the serialization of the MetadataStore object.
- examples: Fix code to catter changes in interfaces.
- examples: Update certificates to avoid SSL KEY TO SMALL errors.
- docs: Significant improvement on the configuration options documentation.
- docs: Fix typos.

- Preserve order of response bindings on IdP-initiated logout
- Fix use of expected binding on SP logout