urlparse fails with AZURE_BLOBS

[mvpatel2000]

Summary

As libcloud uses _ in scheme name, many popular libraries, eg urllib, fail to parse the URIs generated.

In [1]: from urllib.parse import urlparse

In [2]: urlparse('AZURE_BLOBS://data')
Out[2]: ParseResult(scheme='', netloc='', path='AZURE_BLOBS://data', params='', query='', fragment='')