add python 3.9, 3.10, 3.11 support, drop Travis CI configuration for GitHub CI

[fmigneault]

Description

Because some metadata was missing, multiple requirement validators fail to detect the Python 3 support, which flags this package in every other location that it gets used. While at it, I applied the most recent versions of Python 3 to ensure they are tested as well.

Changes

• add missing classifiers and python requirements to setup.py to allow validators to detect appropriate versions
• add python 3.9, 3.10 and 3.11 to the supported versions in setup.py and validate them in Travis CI
• fix test_noaa with the target THREDDS server responding differently than originally tested

[fmigneault]

@cehbrecht
FYI, I refer to eventual tag 0.4.4 in other PRs when this is ready.
This is based on the latest version 0.4.3 from the repository.
However, this release is not available when targeting it (0.4.2 is the latest).

[cehbrecht]

@fmigneault thanks 🙂

[cehbrecht]

This is based on the latest version 0.4.3 from the repository.
However, this release is not available when targeting it (0.4.2 is the latest).

@fmigneault I will upload 0.4.3 to pypi.

[fmigneault]

@cehbrecht
Is it possible to have the mentioned 0.4.4 as well?