Newer PyYAML versions require Python 3.5.
Python 3.4 is EOL for some time and even 3.5 reached EOL recently. So
just switch to that as minimum version.
This makes some minor adjustments, plus some general updates. In short:
* Mark stcgal as stable
* Make tqdm and pyserial requirements more specific
* Add a new long description, specific for PyPI
* Add documentation files to distribution
This adds various tests, integrated into setuptools. These use "monkey
patching" where needed to mock the pyserial and packet reader/writer
functionality to allow for testing with no changes.
The code should be refactored to simplify testing, but this is good enough
to stop regressions for now.
Split up single script into a package with multiple modules.
Also add a setuptools control file. With this, stcgal can be
installed like any other program. It's still possible to launch
from the sources directly. stcgal.py has been converted into a
simple launcher.
v2: fix imports
