See https://github.com/SUNET/SATOSA/pull/135

See https://github.com/SUNET/SATOSA/pull/134

If configured, map AL internal unique id as an attribute to be used
by satosa, microservices and other plugins.

According to the documentation, the id of the user is returned as an
integer (https://developer.github.com/v3/users/). We assume later on
that it is a string so cast it to str here

Explicitly enable signature checking in example config as a sane default

Documentation for new configuration options

Feature refactor saml modules

Fix default values for acr

Allow testers to run specific tests

Add requested authn context for backend requests

Refactor attribute profile initialization

Use acr_mapping from the backend config to generate a
RequestedAuthnContext node in an AuthnRequest.

acr_mapping configuration is extended so that each entry is a dictionary
with two possible keys:
- class_ref: defines the content of the AuthnContextClassRef node
- comparison: defines the Comparison attribute

Until now the command 'tox' would run all of the tests.
With this change one can specify a test to be run by running:

    tox -- path/to/test.py

Select preferred binding on the configuration

pysaml2 supports the configuration option 'preferred_binding' which is
a map of services to array of preferred bindings for that service. Use
the configuration instead of the currently hardcoded choices.

An example configuration would be the following:

  module: satosa.backends.saml2.SAMLBackend
  name: Saml2
  config:
    sp_config:
      preferred_binding:
        single_sign_on_service:
        - urn:oasis:names:tc:SAML:2.0:bindings:HTTP-Redirect
        - urn:oasis:names:tc:SAML:2.0:bindings:HTTP-POST

This defines the preferred bindings for the SSO service, and is
equivalent the code that was hardcoded before. Changing the order of the
bindings would use HTTP-POST instead of the HTTP-Redirect.

Fix codeblocks in Custom attribute release section

Update documentation link for eIDAS Message Format from v1.0 to v1.1-2