README.asciidoc: Wrap super-long line
Require HTTP 200 from os-keypairs in CreateKeyPair
osutil.AuthOptions appends /tokens to provider

if not already present.

A typical `OS_AUTH_URL` is:

```
OS_AUTH_URL=http://<hostname>:5000/v2.0
```

We need to append "/tokens" to this in order for auth calls to work.

Sample program: https://gist.github.com/msabramo/e21a6d3a24c5aa3441c6
PopulateApi return an error for unknown variant

Before this, you could pass any variant name you wanted and if it didn't
match "rackspace" or "openstack", then we'd return a blank ApiCriteria.
This would cause code that's trying to talk to, say, Compute, to get the
first service in the catalog, regardless of whether it's the one that
they wanted.
Merge pull request #173 from msabramo/README_wrap_long_line

README.asciidoc: Wrap super-long line
Merge pull request #174 from msabramo/require_HTTP_200_from_CreateKeyPair

Require HTTP 200 from os-keypairs in CreateKeyPair
Merge pull request #177 from msabramo/more_informative_endpoint_error

Make "Missing endpoint..." error more informative
Merge pull request #176 from msabramo/PopulateApi_return_error_for_unknown_variant

PopulateApi return an error for unknown variant
Merge pull request #175 from msabramo/osutil.AuthOptions_append_tokens_to_provider

osutil.AuthOptions appends /tokens to provider
Make "Missing endpoint..." error display ServiceCatalog

This makes it easier to debug why we failed to get a URL.