Add a setup.cfg keywords to describe taskflow

Include keywords that will be searchable on
pypi (and any indexing sites) that describe
in single words what taskflow is all about.

Change-Id: I8971707044e92e330fed73c485f10ecd5244445f
Minor cleanup in test_examples

- check process exit code instead of stderr emptiness;
- in case of failure include stderr and stdout of example into
  exception message.

Change-Id: I3957810c8ac0621bafa4eda85e089071d96c794e
Put SQLAlchemy requirements on single line

Pip seems to have 'one name, one line' requirement for requirements,
and does not merge them, raising error instead.

Closes-bug: #1271093
Change-Id: I9e573a6a4de844992eb477393df867a734cbb536
Merge "Add a setup.cfg keywords to describe taskflow"
Merge "Minor cleanup in test_examples"