Migrate from nosetest to pytest

nosetest doesn't support python 3.10 and over the years the python
community has been settling on pytest as test runner, this change
introduces pytest and adds py3.10 to the gh workflow testing matrix.

.github/workflows/tox.yaml

@@ -9,7 +9,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        python-version: [3.8, 3.9]
+        python-version: ["3.8", "3.9", "3.10"]
 
     steps:
     - uses: actions/checkout@v1
@@ -19,6 +19,7 @@ jobs:
         python-version: ${{ matrix.python-version }}
     - name: Install dependencies
       run: |
+        sudo apt-get install -q --yes libxml2-dev libxslt1-dev
         python -m pip install --upgrade pip
         pip install tox tox-gh-actions
     - name: Lint with tox

requirements.txt

@@ -18,7 +18,8 @@ flake8-per-file-ignores
 pydocstyle<4.0.0
 coverage<6.0.0  # coverage 6.0+ drops support for py3.5/py2.7
 mock>=1.2
-nose>=1.3.7
+pytest
+pytest-cov
 pbr>=1.8.0,<1.9.0
 simplejson>=2.2.0
 netifaces>=0.10.4

tox.ini

@@ -24,7 +24,7 @@ setenv = VIRTUAL_ENV={envdir}
 install_command =
   {toxinidir}/pip.sh install {opts} {packages}
 
-commands = nosetests --with-coverage --cover-package=zaza.openstack {posargs} {toxinidir}/unit_tests
+commands = pytest --cov=zaza.openstack {posargs} {toxinidir}/unit_tests
 
 [testenv:py3]
 basepython = python3
@@ -38,6 +38,10 @@ deps = -r{toxinidir}/requirements.txt
 basepython = python3.9
 deps = -r{toxinidir}/requirements.txt
 
+[testenv:py3.10]
+basepython = python3.10
+deps = -r{toxinidir}/requirements.txt
+
 [testenv:pep8]
 basepython = python3
 deps = -r{toxinidir}/requirements.txt