fix format of result of extensions query and related functions
Merge pull request #172 from jrperritt/fix-os-identity-format

Fix os identity format
add versioning to identity; add generic 'client' function
add comments
change name of 'ClientOpts' to 'EndpointOpts'
don't use region environment variable
return error if no endpoint found
Merge pull request #181 from jrperritt/os-identity-endpoint-fix

Os identity endpoint fix
move 'NewClient' to function