Release 1.12.0

Additions in this release:

• New function network in the network_utils module. It is a companion to net and takes the same arguments, but returns only one value (the response). If an error occurs, it raises the error as an exception. This makes it possible for callers to use network(...) in somewhat more Pythonic style than net(...), by wrapping the call to network(...) in try-except.

Changes in this release:

• Removed slice from data_utils module because it shadows a Python built-in.
• Fixed hostname in network_utils to be more general and not hardwire a test for http.
• Fixed a bunch of flake8 warnings.