CI fixes

Actually run CI, because that generally helps -- sigh. :) Also update the Python
versions, bump action versions, install test dependency, and don't fail fast if
a particular version fails.

.github/workflows/python.yaml

@@ -1,32 +1,36 @@
 name: Tests
 
-on: [push]
+on:
+  push:
+    branches: [master]
+  pull_request:
 
 jobs:
   test:
     runs-on: ubuntu-latest
     strategy:
+      fail-fast: false
       matrix:
-        python-version: ['2.7', '3.7', '3.8', '3.9', '3.10']
+        python-version: ['3.8', '3.9', '3.10', '3.11', '3.12']
 
     steps:
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@v3
     - name: Set up Python ${{ matrix.python-version }}
-      uses: actions/setup-python@v2
+      uses: actions/setup-python@v4
       with:
         python-version: ${{ matrix.python-version }}
     - name: Install dependencies
       run: |
         python -m pip install --upgrade pip
-        pip install coveralls nose2 pylint setuptools wheel
+        pip install coveralls nose2 pylint setuptools wheel dpkt
     - name: Test with nose2
       run: |
         cd tests && nose2 -C --coverage ../communityid --coverage-report term-missing communityid_test
     - name: Build package
       run: |
         python setup.py sdist bdist_wheel
     - name: Preserve built package
-      uses: actions/upload-artifact@v2
+      uses: actions/upload-artifact@v3
       with:
         name: communityid-py${{ matrix.python-version }}.tar.gz
         path: dist/*.tar.gz