Ensure no double slash in get token URL

Before appending a slash to an URL, we should make sure
that the url doesn't already have one at the end.

Change-Id: Iff864d9b49cf3e3138f602a2c6615ed742f35698
Closes-Bug: 1337880
Docstrings for usability.

The keystoneclient docstrings should give guidance for an
application developer to actually use the library. Here's a start.

Partial-Bug: #1330769
Change-Id: I1a9434704d0cd6b58de76933ff78c8d5c0aa3e3b
Use jsonutils to load adapter response

This is not technically needed, however we and the libraries we use,
aren't very good about keeping our strings and bytes straight for python
3. jsonutils has an attempt to decode stage that means we can let it
manage the correct types.

Change-Id: I2caf4a5b9a04495aa0286f2b6e3193a17ff246e5
Merge "Ensure no double slash in get token URL"
Merge "Docstrings for usability."
SAML2 ECP auth plugin

Auth plugin authenticating against remote SAML based Identity Providers.
Upon successful authentication the plugin retrieves and stores unscoped token.
Plugin object should be later used for scoping the token.

Currently only HTTP BasicAuth Method is supported as
an IdP authn method.

Will not work for ADFS, as that has extensions to the document formats
as well as a different workflow.

Change-Id: Ieea40505a406bedf7219fa6f9e6cf29a45ad6e88
Implements: blueprint add-saml2-cli-authentication
Merge "Use jsonutils to load adapter response"
Merge "SAML2 ECP auth plugin"