Pip and arrow are both complaining about the presence of v3.4.
From the travis log
0.82s$ pip install .
DEPRECATION: Python 3.4 support has been deprecated. pip 19.1 will be the last one supporting it. Please upgrade your Python as Python 3.4 won't be maintained after March 2019 (cf PEP 429).
Processing /home/travis/build/davesteele/topydo
Collecting arrow>=0.7.0 (from topydo==0.13)
Downloading a3d20e80ee/arrow-0.14.2-py2.py3-none-any.whl
ERROR: arrow requires Python '>=2.7, !=3.0.*, !=3.1.*, !=3.2.*, !=3.3.*, !=3.4.*' but the running Python is 3.4.8
The command "pip install ." failed and exited with 1 during .
Your build has been stopped.
On Travis CI, the pypy3 tests may fail due to concurrency issues,
probably because of the usage of (shared) temporary files.
So, limit the number of processes used by green to 1 when pypy3 is used.
This implies that failures for pypy3 are no longer allowed.
Supporting Python 2 resulted in some additional dependencies (six,
ushlex, get_terminal_size). Removing 2.7 support makes things a bit
easier and maintainable.
It's a 4 year old version of Python and some libraries are no longer
supporting it anymore. This removes some hairy code to support Python
3.2 any longer.
The trigger is that pylint doesn't support Python 3.2 anymore, and in
that case Travis CI should not run pylint.
This script takes an optional argument for the executable name of the
corresponding Python version (typically just 'python2' and 'python3').
When not given, 'python' is just run, whatever is in your $PATH. The
latter mode is used in Travis CI.