This allows a python3-based tox (as is common on modern debian/ubuntu
systems) to test our py2-only package. The first thing Tox does is to build a
wheel to install into the target virtualenv (which is a py2-based venv, for
tahoe). But Tox bug (https://github.com/tox-dev/tox/issues/507) in which this
wheel is built with the same python that Tox is using, instead of the python
from the target environment. Our setup.py would see sys.version_info with py3
and launch a crowbar into the works.
With python_requires=, pip is smart enough to know that it's ok to build
wheels with the wrong python, but "pip install" still throws a sensible error
message:
```
(ve36) ~/stuff/tahoe/tahoe$ pip install .
Processing /home/warner/stuff/tahoe/tahoe
tahoe-lafs requires Python '<3.0' but the running Python is 3.6.1
```
Closes ticket:2876
This removes some code in dictutil.py that we weren't using, or which could
be replaced by something simpler. This code is troublesome, because our unit
tests only achieve intermittent coverage, so other (unrelated) PRs are
failing CI when the coverage appears to go down.
I tried to improve the tests to reliably cover everything in dictutil.py, and
discovered code that couldn't possibly have worked in the first place. So the
easiest approach was just to delete it all.
refs ticket:2891
It looks like str() was meant to truncate the dict, but a missing i+=1 meant
that it never actually did. I also changed the format to include a clear
"..." in case we truncate it, to avoid confusion with a non-truncated dict of
the same size.
This also improves test coverage in subtract() and
NumDict.item_with_largest_value().
refs ticket:2891
travis apparently behaves like buildbot's ERROR_UPON_ERROR, rather that
HALT_UPON_ERROR, and if the tor install fails, then the integration test's
last step is certain to fail.
This opens a wormhole and sends appropriate JSON down
it to a tahoe-gui using a wormhole server running on
tahoe-lafs.org
The other end uses the 'tahoe create-node' command (with
new --join option) to read the configuration JSON from
a 'tahoe invite' command
