Flash multiple microbits at once

[tomviner]

Fix for https://github.com/ntoll/uflash/issues/18 Flash multiple microbits at once

The target argument can now occur any number of times.

$ uflash --help
usage: uflash [-h] [-r RUNTIME] [-e] [source] [target [target ...]]

i.e.

$ uflash setup.py /media/tom/MICROBIT /media/tom/MICROBIT1
Flashing Python to: /media/tom/MICROBIT/micropython.hex
Flashing Python to: /media/tom/MICROBIT1/micropython.hex

On Linux this allows shell expansions like:

$ uflash setup.py /media/tom/MICROBIT*
Flashing Python to: /media/tom/MICROBIT/micropython.hex
Flashing Python to: /media/tom/MICROBIT1/micropython.hex

or

$ uflash setup.py /media/tom/MICROBIT{,3,5}
Flashing Python to: /media/tom/MICROBIT/micropython.hex
Flashing Python to: /media/tom/MICROBIT3/micropython.hex
Flashing Python to: /media/tom/MICROBIT5/micropython.hex

Note: uflash does not receive (and cannot deal with) strings like /media/tom/MICROBIT*, rather shell expansion takes place, so the actual args passed into the script are /media/tom/MICROBIT /media/tom/MICROBIT1.

Windows doesn't do shell expansion, and even the glob module cannot reference multiple volumes, i.e. glob.glob('*:\\MICROBIT') never matches anything. So on Windows, one must pass n paths for n microbits. And the docs update shows just this - no * or {}.

Full list of changes:

• Run tests via tox - to test against Pythons 2.7, 3.3, 3.4 & 3.5.
• Add travis-ci config (you'll have to configure this if you'd like this setup for this repo @ntoll)
• Fix broken 'print' test on Python 2.7
• Improve unsupported OS error message - name the OS
• Update Authors file
• Isort - re-order imports
• Use mock.mock_open rather than a load of __enter__ __exit__ mocking
• Fix tests for Windows - / v \
• Add linting to tox (your make pyflakes / pep8 commands are broken btw - I couldn't workout how to fix them without just listing the files we want, which is what I've done in tox.ini)
• Add pytest-cov and coveralls config (again @ntoll, if you want it, you'll need to turn it on. Go here. You'll probably want to turn the emails off.)
• Add support for passing multiple microbit paths
• Update docs
• Update changelog

Happy to alter / take any of these changes out, if they don't seem appropriate. Everything is in separate commits.

If you'd like Appveyor to run the tests on Windows automatically, I can add that too (in a separate PR).

[ntoll]

@tomviner this is great stuff! I've had a look around your changes but will need a bit more time to look in more detail. Put simply, I think this is wonderful but I need to update the docs as per your instructions and make some tox related changes before merging into master. Shouldn't take too long, although it ain't gonna happen today.

Thank you! :-)

[ntoll]

OK... I fixed a couple of niggles and merged. It works! Yay! Many many thanks for the contribution @tomviner.

[tomviner]

Great!